Specialized mobile light device configured with a gallium and nitrogen containing laser source

ABSTRACT

A portable lighting apparatus is provided with a gallium-and-nitrogen containing laser diode based white light source combined with an infrared illumination source which are driven by drivers disposed in a printed circuit board assembly enclosed in a compact housing and powered by a portable power supply therein. The portable lighting apparatus includes a first wavelength converter configured to output a white-color emission and an infrared emission. A beam shaper may be configured to direct the white-color emission and the infrared emission to a front aperture of a compact housing of the portable lighting apparatus. An optical transmitting unit is configured to project or transmit a directional light beam of the white light emission and/or the infrared emission for illuminating a target of interest, transmitting a pulsed sensing signal or modulated data signal generated by the drivers therein. In some configurations, detectors are included for depth sensing and visible/infrared light communications.

BACKGROUND

In the late 1800's, Thomas Edison invented the light bulb. Theconventional light bulb, commonly called the “Edison bulb,” has beenused for over one hundred years for a variety of applications includinglighting and displays. The conventional light bulb uses a tungstenfilament enclosed in a glass bulb sealed in a base, which is screwedinto a socket. The socket is coupled to an AC power or DC power source.The conventional light bulb can be found commonly in houses, buildings,and outdoor lightings, and other areas requiring light or displays.Unfortunately, drawbacks exist with the conventional light bulb:

-   -   The conventional light bulb dissipates more than 90% of the        energy used as thermal energy.    -   The conventional light bulb routinely fails due to thermal        expansion and contraction of the filament element.    -   The conventional light bulb emits light over a broad spectrum,        much of which is not perceived by the human eye.    -   The conventional light bulb emits in all directions, which is        undesirable for applications requiring strong directionality or        focus, e.g. projection displays, optical data storage, etc.

To overcome some of the drawbacks of the conventional light bulb,several alternatives have been developed including fluorescent lamps,Mercury vapor lamps, sodium vapor lamps, other high-intensity discharge(HID) lamps, gas discharge lamps such as neon lamps, among others. Theselamp technologies in general suffer from similar problems to Edisonlamps as well as having their own unique drawbacks. For example,fluorescent lamps require high voltages to start, which can be in therange of a thousand volts for large lamps, and also emit highlynon-ideal spectra that are dominated by spectral lines.

In the past decade, solid state lighting has risen in importance due toseveral key advantages it has over conventional lighting technology.Solid state lighting is lighting derived from semiconductor devices suchas diodes which are designed and optimized to emit photons. Due to thehigh efficiency, long lifetimes, low cost, and non-toxicity offered bysolid state lighting technology, light emitting diodes (LED) haverapidly emerged as the illumination technology of choice. An LED is atwo-lead light source typically based on a p-i-n junction diode, whichemits electromagnetic radiation when activated. The emission from an LEDis spontaneous and is typically in a Lambertian pattern. When a suitablevoltage is applied to the leads, electrons and holes recombine withinthe device releasing energy in the form of photons. This effect iscalled electroluminescence, and the color of the light is determined bythe energy band gap of the semiconductor.

Appearing as practical electronic components in 1962 the earliest LEDsemitted low-intensity infrared light. Infrared LEDs are still frequentlyused as transmitting elements in remote-control circuits, such as thosein remote controls for a wide variety of consumer electronics. The firstvisible-light LEDs were also of low intensity, and limited to red.Modern LEDs are available across the ultraviolet and infraredwavelengths, with very high brightness.

The earliest blue and violet gallium nitride (GaN)-based LEDs werefabricated using a metal-insulator-semiconductor structure due to a lackof p-type GaN. The first p-n junction GaN LED was demonstrated by Amanoet al. using the LEEBI treatment to obtain p-type GaN in 1989. Theyobtained the current-voltage (I-V) curve and electroluminescence of theLEDs, but did not record the output power or the efficiency of the LEDs.Nakamura et al. demonstrated the p-n junction GaN LED using thelow-temperature GaN buffer and the LEEBI treatment in 1991 with anoutput power of 42 μW at 20 mA. The first p-GaN/n-InGaN/n-GaN DH blueLEDs were demonstrated by Nakamura et al. in 1993. The LED showed astrong band-edge emission of InGaN in a blue wavelength regime with anemission wavelength of 440 nm under a forward biased condition. Theoutput power and the EQE were 125 μW and 0.22%, respectively, at aforward current of 20 mA. In 1994, Nakamura et al. demonstratedcommercially available blue LEDs with an output power of 1.5 mW, an EQEof 2.7%, and the emission wavelength of 450 nm. On Oct. 7, 2014, theNobel Prize in Physics was awarded to Isamu Akasaki, Hiroshi Amano andShuji Nakamura for “the invention of efficient blue light-emittingdiodes which has enabled bright and energy-saving white light sources”or, less formally, LED lamps.

By combining GaN-based LEDs with wavelength converting materials such asphosphors, solid-state white light sources were realized. Thistechnology utilizing GaN-based LEDs and phosphor materials to producewhite light is now illuminating the world around us as a result of themany advantages over incandescent light sources including lower energyconsumption, longer lifetime, improved physical robustness, smallersize, and faster switching. LEDs are now used in applications as diverseas aviation lighting, automotive headlamps, advertising, generallighting, traffic signals, and camera flashes. LEDs have allowed newtext, video displays, and sensors to be developed, while their highswitching rates can be very useful in communications technology. LEDs,however, are not the only solid-state light source and may not bepreferable light sources for certain lighting applications. Alternativesolid state light sources utilizing stimulated emission, such as laserdiodes (LDs) or super-luminescent light emitting diodes (SLEDs), providemany unique features advantageously over LEDs.

In 1960, the laser was demonstrated by Theodore H. Maiman at HughesResearch Laboratories in Malibu. This laser utilized a solid-state flashlamp-pumped synthetic ruby crystal to produce red laser light at 694 nm.Early visible laser technology comprised lamp pumped infrared solidstate lasers with the output wavelength converted to the visible usingspecialty crystals with nonlinear optical properties. For example, agreen lamp pumped solid state laser had 3 stages: electricity powerslamp, lamp excites gain crystal which lases at 1064 nm, 1064 nm goesinto frequency conversion crystal which converts to visible 532 nm. Theresulting green and blue lasers were called “lamped pumped solid statelasers with second harmonic generation” (LPSS with SHG) had wall plugefficiency of ˜1%, and were more efficient than Ar-ion gas lasers, butwere still too inefficient, large, expensive, fragile for broaddeployment outside of specialty scientific and medical applications. Toimprove the efficiency of these visible lasers, high power diode (orsemiconductor) lasers were utilized. These “diode pumped solid statelasers with SHG” (DPSS with SHG) had 3 stages: electricity powers 808 nmdiode laser, 808 nm excites gain crystal, which lases at 1064 nm, 1064nm goes into frequency conversion crystal which converts to visible 532nm. As high-power laser diodes evolved and new specialty SHG crystalswere developed, it became possible to directly convert the output of theinfrared diode laser to produce blue and green laser light output. These“directly doubled diode lasers” or SHG diode lasers had 2 stages:electricity powers 1064 nm semiconductor laser, 1064 nm goes intofrequency conversion crystal which converts to visible 532 nm greenlight. These lasers designs are meant to improve the efficiency, costand size compared to DPSS-SHG lasers, but the specialty diodes andcrystals required make this challenging today.

Solid-state laser light sources, due to the narrowness of their spectrawhich enables efficient spectral filtering, high modulation rates, andshort carrier lifetimes, smaller in size, and far greater surfacebrightness compared to LEDs, can be more preferable as visible lightsources as a means of transmitting information with high bandwidth inmany applications including lighting fixtures, lighting systems,displays, projectors and the like. Advancements of new GaN-based bluelaser technology based on improved processes have substantially reducedmanufacture cost and opened opportunities for utilizing the modulatedlaser signal and the light spot directly to measure and or interact withthe surrounding environment, transmit data to other electronic systems,and respond dynamically to inputs from various sensors. Suchapplications are herein referred to as “smart lighting” applications tobe disclosed throughout the specification herein.

SUMMARY

The present invention provides a portable apparatus configured with awhite-light and/or an infrared (IR) illumination source based on agallium and nitrogen containing laser diodes in surface mount devices.With the capability to emit light in both the visible spectrum and theinfrared spectrum, the portable apparatus is optionally a dual-bandemitting light source with either or both being applied for distanceranging and/or light communication. In some embodiments the gallium andnitrogen containing laser diode is fabricated with a process to transfergallium and nitrogen containing layers and methods of manufacture anduse thereof. In some embodiments, the portable apparatus includes ahousing that is configured to be a compact, portable, or handheldpackage containing controller/drivers, transmitters, andsensors/detectors to form feedback loops that can activate the infraredillumination source and/or the laser-based white light illuminationsource, modulate the light signals transmitted out of these sourcesbased on certain input data, and detect light signals returned fromfield for various applications. Merely by examples, the inventionprovides integrated smart laser lighting devices and methods, configuredwith infrared and visible illumination capability for spotlighting,detection, imaging, projection display, spatially dynamic lightingdevices and methods, depth finding, infrared surveying, andvisible/infrared light communication devices and methods, and variouscombinations of above in applications of general lighting, commerciallighting and display, automotive lighting and communication, defense andsecurity, search and rescue, industrial processing, internetcommunications, agriculture or horticulture. The portable integratedlight source according to this invention can be miniaturized toincorporate those functions into a flashlight, a hand-held illuminationsource or security light source or a search light source or a defenselight source, as well as a light fidelity (LiFi) communication device ora device for horticulture purposes to optimize plant growth, or manyother applications.

In an aspect, this invention provides novel uses and configurations ofgallium and nitrogen containing laser diodes in lighting systemsconfigured for IR illumination, which can be deployed in dual spectrumspotlighting, imaging, sensing, and searching applications. Configuredwith a laser based white light source and an IR light source, thisinvention is capable of emitting light both in the visible wavelengthband and in the IR wavelength band, and is configured to selectivelyoperate in one band or simultaneously in both bands. This dual bandemission source can be deployed in communication systems such as visiblelight communication systems such as Li-Fi systems, communications usingthe convergence of lighting and display with static or dynamic spatialpatterning using beam shaping elements such as MEMS scanning mirrors ordigital light processing units, and communications triggered byintegrated sensor feedback. Specific embodiments of this inventionemploy a transferred gallium and nitrogen containing material processfor fabricating laser diodes or other gallium and nitrogen containingdevices enabling benefits over conventional fabrication technologies.

The present invention is configured for both visible light emission andIR light emission. While the necessity and utility of visible light isclearly understood, it is often desirable to provide illuminationwavelength bands that are not visible. In one example, IR illuminationis used for night vision. Night vision or IR detection devices play acritical role in defense, security, search and rescue, and recreationalactivities in both the private sector and at the municipal or governmentsectors. By providing the ability to see in no or low ambient lightconditions, night vision technology is widely deployed to the consumermarkets for several applications including hunting, gaming, driving,locating, detecting, personal protection, and others. Whether bybiological or technological means, night vision and IR detection aremade possible by a combination of sufficient spectral range andsufficient intensity range. Such detection can be for two-dimensionalimaging, or three-dimensional distance measurement such asrange-finding, or three-dimensional imaging such as LIDAR.

In an aspect, the present invention provides a portable light sourceconfigured for emission of laser-based visible light such as white lightand an infrared light, to form an illumination source capable ofproviding visible and IR illumination. The portable light sourceincludes a compact power supply enclosed in a housing structureconfigured to be as small as a handheld flashlight. The portable lightsource includes an integrated printed circuit board assembly disposed inthe housing for driving a gallium and nitrogen containing laser diodeexcitation source configured with an optical cavity. The optical cavityincludes an optical waveguide region and one or more facet regions. Theoptical cavity is configured with electrodes to supply a first drivingcurrent to the gallium and nitrogen containing material. The firstdriving current provides an optical gain to an electromagnetic radiationpropagating in the optical waveguide region of the gallium and nitrogencontaining material. The electromagnetic radiation is outputted throughat least one of the one or more facet regions as a directionalelectromagnetic radiation characterized by a first peak wavelength inthe ultra-violet, blue, green, or red wavelength regime. Furthermore,the light source includes a wavelength converter, such as a phosphormember, optically coupled to the pathway to receive the directionalelectromagnetic radiation from the excitation source. The wavelengthconverter is configured to convert at least a fraction of thedirectional electromagnetic radiation with the first peak wavelength toat least a second peak wavelength that is longer than the first peakwavelength. In a preferred embodiment the output is comprised of awhite-color spectrum with at least the second peak wavelength andpartially the first peak wavelength forming the laser based visiblelight spectrum component according to the present invention. In oneexample, the first peak wavelength is a blue wavelength and the secondpeak wavelength is a yellow wavelength. The light source optionallyincludes a beam shaper configured to direct the white-color spectrum forilluminating a target or area of interest.

In one preferred embodiment, the present invention provides a dual bandemitting light source including an IR emitting laser diode or lightemitting diode to form the IR emission component in additional to alaser-based white light emission component. The IR emitting laser diodecontains an optical cavity configured with electrodes to supply a seconddriving current. The second driving current provides an optical gain toan IR electromagnetic radiation propagating in the optical waveguideregion. The electromagnetic radiation is outputted through at least oneof the one or more facet regions as a directional electromagneticradiation characterized by a third peak wavelength in the IR regime. Inone configuration the directional IR emission is optically coupled tothe wavelength converter member such that the wavelength convertermember is within the optical pathway of the IR emission to receive thedirectional electromagnetic radiation from the excitation source. Onceincident on the wavelength converter member, the IR emission with thethird peak wavelength would be at least partially reflected from thewavelength converter member and redirected into the same optical pathwayas the white light emission with the first and second peak wavelengths.The IR emission would be directed through the optional beam shaperconfigured to direct the output IR light for illuminating approximatelythe same target or area of interest as the visible light. In thisembodiment the first and second driving current could be activatedindependently such that the apparatus could provide a visible lightsource with only the first driving current activated, an IR light sourcewith the second driving current activated, or could simultaneouslyprovide both a visible and IR light source. In some applications itwould be desirable to only use the IR illumination source for IRdetection. Once an object was detected, the visible light source couldbe activated.

Optionally, a second wavelength converter member is included to provideemission in the IR regime at a third peak wavelength, to provide the IRemission component of the dual band emitting light source. The IRwavelength converter member, such as a phosphor member, would beconfigured to receive and absorb a pump light and emit a longerwavelength IR light. In this embodiment, the dual band light sourcecomprises the first wavelength converter member for emitting visiblelight and the second wavelength converter member for emitting IR light.In one example, the first and second wavelength converter members areconfigured in a side by side, or adjacent arrangement such that thewhite light emission from the first wavelength converter member isemitted from a separate spatial location than the IR emission from thesecond wavelength converter member. In this example, the first andsecond wavelength converter members could be excited by separate laserdiode members wherein in one embodiment the first wavelength convertermember would be excited by a first gallium and nitrogen containing laserdiodes such as violet, blue, or green laser diodes, and the secondwavelength converter member would be excited by a second gallium andnitrogen containing laser diodes such as violet, blue, or green laserdiodes. In a second embodiment of this example the first wavelengthconverter member is excited by a first gallium and nitrogen containinglaser diode such as a violet or blue laser diode, and the secondwavelength converter member is excited by a second laser diode formedfrom a different material system operating in the red or IR wavelengthregion, such as a gallium and arsenic containing material or an indiumand phosphorous containing material. In these embodiments the firstlaser diode would be excited by a first drive current and the secondlaser diode would be excited by a second drive current. Since the firstand second drive currents could be activated independently, the dualband light emitting source could provide a visible light source withonly the first driving current activated, an IR light source with onlythe second driving current activated, or could simultaneously provideboth a visible and IR light source with both the first and second drivecurrents activated. In some applications it would be desirable to onlyuse the IR illumination source for IR detection. Once an object isdetected with the IR illumination, the visible light source can beactivated to visibly illuminate the target.

Optionally, the first wavelength converter member and the secondwavelength converter member could be configured in a vertically stackedarrangement. Preferably the first wavelength converter member would bearranged on the same side as the primary emission surface of the stackedwavelength converter arrangement such that the IR light emitted from thesecond wavelength converter can pass through the first wavelengthconverter member without appreciable absorption. That is, in areflective mode configuration, the first wavelength converter memberemitting the visible light would be arranged on top of the secondwavelength converter member emitting the IR light such that the visibleand IR emission exiting the emission surface of the first wavelengthconverter would be collected as useful light. That is, the IR emissionwith the third peak wavelength would be emitted into the same opticalpathway as the white light emission with the first and second peakwavelengths. In this stacked configuration, a common gallium andnitrogen containing laser diode member could be configured as theexcitation source for both the first and second wavelength member. Sincethe IR and visible light emission would exit the stacked wavelengthconverter members from the same surface and within approximately thesame area, a simple optical system such as collection and collimationoptics can be used to project and direct both the visible emission andthe IR emission to the same target area. In this configurationactivating the laser diode member with a first drive current wouldexcite both the emission of the visible light and the IR light such thatindependent control of the emission of the visible light and IR lightwould be difficult. Other vertically stacked wavelength convertermembers are possible such as positioning the IR emitting secondwavelength converter member on the emission side of the stack such thatthe visible light emission from the first wavelength converter memberwould function to excite IR emission from the second wavelengthconverter member.

In the example with the vertically stacked wavelength converter membersthe first and second wavelength converter members could be excited byseparate laser diode members. Optionally, the first wavelength convertermember would be excited by a first gallium and nitrogen containing laserdiodes such as violet or blue laser diode and the second wavelengthconverter member would be excited by a second gallium and nitrogencontaining laser diodes such as a green emitting or longer wavelengthlaser diode. Optionally, the first wavelength converter member isexcited by a first gallium and nitrogen containing laser diode such as aviolet or blue laser diode, and the second wavelength converter memberis excited by a second laser diode formed from a different materialsystem operating in the red or IR wavelength region, such as a galliumand arsenic containing material or an indium and phosphorous containingmaterial. The key consideration for this embodiment is to select thesecond laser diode with an operating wavelength that will not besubstantially absorbed in the first wavelength converter member, butwill be absorbed in the second wavelength converter member such thatwhen the second laser diode is activated the emission will pass throughthe first wavelength converter to excite the second wavelength converterand generate the IR emission. The result is that the first laser diodemember primarily activates the first wavelength converter member togenerate visible light and the second laser diode member primarilyactivates the second wavelength converter to generate IR light. Thebenefit to this version of the stacked wavelength converterconfiguration is that since the first laser diode would be excited by afirst drive current and the second laser diode would be excited by asecond drive current the first and second wavelength converter memberscould be activated independently such that the dual band light emittingsource could provide a visible light source with only the first drivingcurrent activated, an IR light source with only the second drivingcurrent activated, or could simultaneously provide both a visible and IRlight source with both the first and second drive currents activated. Insome applications it would be desirable to only use the IR illuminationsource for IR detection. Once an object was detected, the visible lightsource could be activated.

Optionally, the first wavelength converter member and the secondwavelength converter member are combined to form single hybridwavelength converter member. This can be achieved in various ways suchas sintering a mixture of wavelength converters elements such asphosphors into a single solid body. In this composite wavelengthconverter configuration, a common gallium and nitrogen containing laserdiode member could be configured as the excitation source to generateboth the visible light and the IR light. In this configuration theactivating the laser diode member with a first drive current wouldexcite both the emission of the visible light and the IR light such thatindependent control of the emission of the visible light and IR lightwould be difficult.

Alternatively, the visible light emission could be excited by a firstgallium and nitrogen containing laser diode such as a violet or bluelaser diode, and the IR emission could be excited by a second laserdiode formed from a different material system operating in the red or IRwavelength region, such as a gallium and arsenic containing material oran indium and phosphorous containing material. The key consideration forthis embodiment is to select the second laser diode with an operatingwavelength that will not be substantially absorbed in the visible lightemitting element of the composite wavelength converter member, but willbe absorbed in IR emitting element of the composite wavelength convertermember such that when the second laser diode is activated it will notexcite the visible light emission, but will excite the IR emission. Theresult is that the first laser diode member primarily activates thefirst wavelength converter member to generate visible light and thesecond laser diode member primarily activates the second wavelengthconverter to generate IR light. Since the IR emission with the thirdpeak wavelength would be emitted from the same surface and spatiallocation as the visible emission with the first and second peakwavelengths, the IR emission would be easily directed into the sameoptical pathway as the white light emission with the first and secondpeak wavelengths. The IR emission and white light emission could then bedirected through the optional beam shaper configured to direct theoutput light for illuminating a target of interest. In this embodimentthe first and second driving current could be activated independentlysuch that the apparatus could provide a visible light source with onlythe first driving current activated, an IR light source with the seconddriving current activated, or could simultaneously provide both avisible and IR light source. In some applications it would be desirableto only use the IR illumination source for IR detection. Once an objectis detected with the IR illumination, the visible light source can beactivated to visibly illuminate the target.

The benefit to this version of the stacked wavelength converterconfiguration is that since the first laser diode would be excited by afirst drive current and the second laser diode would be excited by asecond drive current the first and second wavelength converter memberscould be activated independently such that the dual band light emittingsource could provide a visible light source with only the first drivingcurrent activated, an IR light source with only the second drivingcurrent activated, or could simultaneously provide both a visible and IRlight source with both the first and second drive currents activated. Insome applications it would be desirable to only use the IR illuminationsource for IR detection. Once an object was detected, the visible lightsource could be activated.

In preferred embodiments according to the present invention, thewavelength converter element is comprised of one or more phosphormembers. Such phosphor members can be implemented in solid body formsuch as single crystal phosphor element, a ceramic element, or aphosphor in a glass, or could be in a powder form wherein the powder isbound by a binder material. There is a wide range of phosphorchemistries to select from to ensure the proper emission and performanceproperties. Moreover, such phosphor members can be operated in severalarchitectural arrangements such as a reflective mode, a transmissivemode, a hybrid mode, or any other mode.

In some embodiments, the present disclosure provides a portableapparatus having a dual band light source configured for visible/IRlight communication in a housing structure as compact as a handhelddevice. In the embodiment, the light source includes a controllercomprising a modem and a driver. The modem is configured to receive adata signal. The controller is configured to generate one or morecontrol signals to operate the driver to generate a driving current anda modulation signal based on the data signal. Additionally, the lightsource includes a light emitter configured as a pump-light devicecomprised of a gallium and nitrogen containing material and an opticalcavity. The optical cavity includes an optical waveguide region and oneor more facet regions configured in a surface mount deviceconfiguration. The optical cavity is configured with electrodes tosupply the driving current based on at least one of the one or morecontrol signals to the gallium and nitrogen containing material. Thedriving current provides an optical gain to an electromagnetic radiationpropagating in the optical waveguide region. The electromagneticradiation is outputted through at least one of the one or more facetregions as a directional electromagnetic radiation characterized by afirst peak wavelength in the ultra-violet or blue wavelength regime. Thedirectional electromagnetic radiation is modulated to carry the datasignal using the modulation signal provided by the driver. The lightsource further includes a pathway configured to direct, filter, or splitthe directional electromagnetic radiation. Furthermore, the light sourceincludes a wavelength converter optically coupled to the pathway in thesame surface mount device configuration to receive the directionalelectromagnetic radiation from the pump-light device. The wavelengthconverter is configured to convert at least a fraction of thedirectional electromagnetic radiation with the first peak wavelength toat least a second peak wavelength that is longer than the first peakwavelength and to output a white-color spectrum comprising at least thesecond peak wavelength and partially the first peak wavelength.Moreover, the light source includes a beam shaper configured to directthe white-color spectrum for illuminating a target of interest andtransmitting the data signal through at least the fraction of thedirectional electromagnetic radiation with the first peak wavelength toa receiver at the target of interest.

Optionally, as used herein, the term “modem” refers to a communicationdevice. The device can also include a variety of other data receivingand transferring devices for wireless, wired, cable, or opticalcommunication links, and any combination thereof. In an example, thedevice can include a receiver with a transmitter, or a transceiver, withsuitable filters and analog front ends. In an example, the device can becoupled to a wireless network such as a meshed network, includingZigbee, Zeewave, and others. In an example, the wireless network can bebased upon an 802.11 wireless standard or equivalents. In an example,the wireless device can also interface to telecommunication networks,such as 3G, LTE, 5G, and others. In an example, the device can interfaceinto a physical layer such as Ethernet or others. The device can alsointerface with an optical communication including a laser coupled to adrive device or an amplifier. Of course, there can be other variations,modifications, and alternatives.

Optionally, the pump-light device includes a laser diode device.Optionally, the pump-light device includes a superluminescent diode(SLED) device.

Optionally, the laser diode device includes a carrier chip singulatedfrom a carrier substrate. Additionally, the laser diode device includesone or more epitaxial material die transferred to the carrier substratefrom a substrate. The epitaxial material includes an n-type claddingregion, an active region including at least one active layer overlyingthe n-type cladding region, and a p-type cladding region overlying theactive layer region. Furthermore, the laser diode device includes one ormore laser diode stripe regions formed in the epitaxial material die.

Optionally, the directional electromagnetic radiation with the firstpeak wavelength includes a violet spectrum with the first peakwavelength in a range of 380-420 nm, and/or a blue spectrum with thefirst peak wavelength in a range of 420-480 nm.

According to the present invention, the directional IR electromagneticradiation with the third peak wavelength is emitted from a laser diodeoperating in a range from about 700 nm to about 15000 nm. In one examplethe laser diode operates with wavelength in the 700 nm to 1100 nm rangebased on GaAs for near-IR night vision illumination, range finding andLIDAR sensing, and communication could be included. In another examplethe laser diode operates with wavelength in the 1100 to 2500 nm rangebased on InP for eye-safe wavelength IR illumination, range finding,LIDAR sensing, and communication could be included. The IR emittinglaser diode could be comprised of compound semiconductor materialsincluding GaAs, InP, InGaAs, InAs, InAlAs, AlGaAs, AlInGaP, InGaAsP, orInGaAsSb, or some combination thereof. Additionally, the IR emittinglaser diode could be based on interband electron-hole recombination suchas a quantum well laser-diode, or could be based on quantum cascadelaser diode operating with intraband or interband transitions. Inanother example the laser diode operates with wavelength in the 2500 nmto 15000 nm wavelength range based on quantum cascade laser technologyfor mid-IR thermal imaging, sensing, and communication could beincluded. For example, GaInAs/AlInAs quantum cascade lasers operate atroom temperature in the wavelength range of 3 μm to 8 μm. The IRemitting laser diode is based on an edge-emitting design or a verticalcavity emitting design.

Optionally, the output of the driver includes at least a driving currentfor controlling an intensity of the directional electromagneticradiation emitted from the pump-light device and a modulation signal ofa pre-defined format based on either amplitude modulation or frequencymodulation based on the data signal.

Optionally, the directional electromagnetic radiation includes multiplepulse-modulated light signals at a modulation frequency range selectedfrom about 50 MHz to 300 MHz, 300 MHz to 1 GHz, and 1 GHz to 100 GHzbased on the data signal.

Optionally, the white-color spectrum includes the multiplepulse-modulated light signals modulated based on the data signal carriedby at least a fraction of the directional electromagnetic radiation fromthe light emitter.

Optionally, the wavelength converter includes a phosphor materialconfigured as in a reflection mode to have a surface receiving thedirectional electromagnetic radiation in an incident angle Thewhite-color spectrum is a combination of a spectrum of the second peakwavelength converted by the phosphor material, a fraction of thedirectional electromagnetic radiation with the first peak wavelengthreflected from the surface of the phosphor material, and a fraction ofthe directional electromagnetic radiation scattered from interior of thephosphor material.

Optionally, the wavelength converter includes a phosphor materialconfigured as in a transmission mode to receive the directionalelectromagnetic radiation passed through. The white-color spectrum is acombination of a fraction of the directional electromagnetic radiationnot absorbed by the phosphor material and a spectrum of the second peakwavelength converted by the phosphor material.

Optionally, the wavelength converter includes a plurality of wavelengthconverting regions that respectively convert blue or violet wavelengthregime to a predominantly red spectrum, or a predominantly greenspectrum, and/or a predominantly blue spectrum with a longer peakwavelength than the first peak wavelength of the directionalelectromagnetic radiation.

Optionally, the beam shaper includes a plurality of color-specificoptical elements for independently manipulating the predominantly redspectrum, the predominantly green spectrum, and the predominantly bluespectrum for transmitting to different targets of interests carryingdifferent streams of the data signal for different receivers.

Optionally, the beam shaper includes one or a combination of moreoptical elements selected a list of slow axis collimating lens, fastaxis collimating lens, aspheric lens, ball lens, total internalreflector (TIR) optics, parabolic lens optics, refractive optics, andmicro-electromechanical system (MEMS) mirrors configured to direct,collimate, focus the white-color spectrum to at least modify an angulardistribution thereof.

Optionally, the beam shaper is configured to direct the white-colorspectrum as an illumination source for illuminating the target ofinterest along a preferred direction.

Optionally, the light source includes a beam steering device wherein thebeam steering device is configured to direct the white-color spectrumfor dynamically scanning a spatial range around the target of interest.Optionally, the beam steering device can be selected from amicro-electromechanical system (MEMS) mirror, a digital light processing(DLP) chip, a digital mirror device (DMD), and a liquid crystal onsilicon (LCOS) chip, a lens, a reflector, an amplifier, a projector, aninterferometer for steering, patterning, or pixelating the white-colorlight.

Optionally, the pathway includes an optical fiber to guide thedirectional electromagnetic radiation to the wavelength converter memberdisposed remotely to generate the white-color spectrum. Optionally, thepathway includes a waveguide for guide the directional electromagneticradiation to the wavelength converter member. Optionally, the pathwayincludes free-space optics devices.

Optionally, the receiver at the target of interest comprises aphotodiode, avalanche photodiode, photomultiplier tube, and one or moreband-pass filters to detect pulse-modulated light signals at amodulation frequency range of about 50 MHz to 100 GHz, the receiverbeing coupled to a modem configured to decode the light signals intobinary data.

In another aspect, the present disclosure provides a portable integratedlight source for communication and dynamic spatial illumination or depthfinding. The portable integrated light source includes an internal powersupply enclosed in a compact housing to provide high capacity fordriving multiple laser diodes and corresponding light signal processing,transmission, and detection. The portable integrated light sourcefurther includes a modem configured for receiving data signals and alaser modulation driver coupled to the modem to generate a drivingcurrent and provide a modulation format based on the data signals. Boththe modem and laser modulation driver can be integrated on a singleprinted circuit board assembly which is also disposed in the compacthousing. Additionally, the portable integrated light source includes alaser device driven by the driving current to emit a laser light with afirst peak wavelength modulated according to the modulation format. Theportable integrated light source further includes an optical pathway forguiding the laser light. Furthermore, the portable integrated lightsource includes a wavelength converting element configured to couplewith the optical pathway to receive the laser light with a first peakwavelength and reemit a white-color light excited by converting afraction of the laser light with the first peak wavelength to a spectrumwith a second peak wavelength longer than the first peak wavelength andcombining the fraction of fraction of the laser light with a first peakwavelength and the spectrum with the second peak wavelength. Thewhite-color light carries the data signal in the modulation format.Moreover, the portable integrated light source includes a beam shapingoptical element configured to collimate the white-color light and a beamsteering optical element configured to receive one or more voltage andcurrent signals generated by a beam steering driver based on inputinformation to dynamically scan the white-color light to providepatterned illuminations to multiple areas and simultaneously transmitthe data signals to different receivers at the multiple areas. Also, theportable integrated light source includes one or more sensors orreceivers or detectors configured to detect visible or IR light signalsreturned from field objects for field sensing or distance finding orrange mapping.

Optionally, the modulation format based on the data signal includes oneselected from double-sideband modulation (DSB), double-sidebandmodulation with carrier (DSB-WC), double-sideband suppressed-carriertransmission (DSB-SC), double-sideband reduced carrier transmission(DSB-RC), single-sideband modulation (SSB, or SSB-AM), single-sidebandmodulation with carrier (SSB-WC), single-sideband modulation suppressedcarrier modulation (SSB-SC), vestigial sideband modulation (VSB, orVSB-AM), quadrature amplitude modulation (QAM), pulse amplitudemodulation (PAM), phase-shift keying (PSK), frequency-shift keying(FSK), continuous phase modulation (CPM), minimum-shift keying (MSK),Gaussian minimum-shift keying (GMSK), continuous-phase frequency-shiftkeying (CPFSK), orthogonal frequency-division multiplexing (OFDM), anddiscrete multitone (DMT).

Optionally, the wavelength converting element is disposed via a thermalconductor material on a submount structure commonly supporting the laserdevice. The wavelength converting element includes a phosphor materialselected for absorbing at least partially one of the violet spectrum,the blue spectrum, the green spectrum, and the red spectrum to reemit abroader spectrum with a peak wavelength respectively longer than thepeak wavelength of the wavelength ranges of violet spectrum, the bluespectrum, the green spectrum, and the red spectrum.

Optionally, the beam steering optical element further is selected fromone of a micro-electromechanical system (MEMS) mirror, a digital lightprocessing (DLP) chip, a digital mirror device (DMD), and a liquidcrystal on silicon (LCOS) chip for steering, patterning, or pixelatingthe white-color light.

Optionally, the portable integrated light source further includes amicrocontroller having an interface configured as a user input dial,switch, or joystick mechanism or a feedback loop module for receivinginput information to activate the MEMS mirror, or DLP chip, or DMD, orLCOS chip. Optionally, the microcontroller is also configured with theprinted circuit board assembly in the compact housing. The inputinformation includes an illumination spatial pattern inputted by user ora dynamically varying illumination spatial pattern updated from sensorfeedback. The beam steering optical element further is configured tospatially modulate and dynamically direct the white-color light based onthe input information to provide spatially modulated illumination onto afirst area of a target surface or into first direction of a target spacein a first period and onto a second area of the target surface or into asecond direction of a target space in a second period, and toindependently transmit the data signals to a first receiver at the firstarea or downstream in the first direction in the first period and to asecond receiver at the second area or downstream in the second directionin the second period.

Optionally, the beam steering optical element includes a reflectordisposed at downstream of the white-color light outputted from thewavelength converting member in the surface mount device configuration.The reflector is a parabolic reflector to reflect and propagate acollimated beam along an axis thereof.

Optionally, the beam steering optical element further includes a lensdisposed at an aperture of the compact housing and used to collimate thewhite-color light into a projected beam. The lens includes an asphericlens positioned the wavelength converting element to collimate thewhite-color light.

Optionally, the beam steering optical element of the portable integratedlight source further is configured to dynamically output the IRillumination light.

Optionally, the compact housing of the portable integrated light sourceis configured to have a common submount to support at least the laserdevice including both gallium and nitrogen blue-laser diode and infraredlaser-diode, the wavelength converting element for either the blue laseror IR laser. The common submount is integrated in one of a TO canisterpackage, a butterfly package, a chip and phosphor on submount (CPoS)package, a surface mount device (SMD) type package. The housing is alsoconfigured to have an assembly to hold the internal power supply like ahigh capacity battery and a printed circuit board on which multiplechips of the drivers and microcontroller are installed. Optionally, thehousing has a user interface panel containing switch button, datascreen, data I/O port, charging port, etc.

In another aspect, the present disclosure provides a portable apparatuswith a dynamic light source with color and brightness control forvisible light communication. The portable apparatus includes a compacthousing with a built-in power supply. The portable apparatus alsoincludes a modem configured to receive digital information forcommunication. Additionally, the portable apparatus includes a laserdriver mounted on a printed circuit board assembly configured togenerate a driving current and at least one modulation signal based onthe digital information. The portable apparatus further includes agallium Ga and nitrogen N containing laser device in a surface mountdevice package configured to be driven by the driving current to emit alaser beam with a first peak wavelength in a color range of violet orblue spectrum. The laser beam is modulated by the at least onemodulation signal to carry the digital information. Optionally, theportable apparatus further includes an IR laser diode fabricated in thesame surface mount device package as the GaN laser diode and configuredto generate a directional IR electromagnetic radiation. Furthermore, theportable apparatus includes a beam shaping optical element configured todynamically direct the laser beam with a varying angle through anaperture into a pathway. The portable apparatus further includes awavelength converting member comprising at least two color phosphorregions spatially distributed to respectively receive the laser beamwith different angle outputted from the pathway and configured toconvert a fraction of the laser beam with the first peak wavelength toat least two color spectra respectively by the at least two colorphosphor regions. Each of the at least two color spectra includes asecond peak wavelength longer than the first peak wavelength but varyingwith the fraction of the laser beam being absorbed by each of the atleast two color phosphor regions. The at least two color spectra arerespectively combined with remaining fraction of the laser beam with thefirst peak wavelength to reemit an output light beam of a broaderspectrum with a dynamically varied color point. Optionally, thedirectional IR electromagnetic radiation includes a third peakwavelength in infrared frequency range. The portable apparatus alsoincludes a beam steering optical element disposed in the housing betweenan aperture and the output light beam and configured to spatiallydirect, transmit, or project the output light beam. Moreover, thedynamic light source includes a beam steering driver mounted also on thesame printed circuit board assembly and configured to generate controlsignals based on input information for the beam steering optical elementto dynamically scan or project the output light beam to providespatially modulated illumination with dynamically varied color pointonto one or more of multiple target areas or into one or more ofmultiple target directions in one or more selected periods whilesimultaneously transmit digital information to a receiver in one or moreof multiple target areas or one or more of multiple target directions inone or more selected periods.

Optionally, the gallium and nitrogen containing laser device includesone or more laser diodes for emitting the laser beam with the first peakwavelength in violet spectrum ranging from 380 to 420 nm, in bluespectrum ranging from 420 to 480 nm, in the cyan and green spectrumranging from 480 to 560 nm, or longer.

According to the present invention, the directional IR electromagneticradiation with the third peak wavelength is emitted from an IR laserdiode operating in a range from about 700 nm to about 15000 nm. In oneexample the laser diode operates with wavelength in the 700 nm to 1100nm range based on GaAs for near-IR night vision illumination, rangefinding and LIDAR sensing, and communication could be included. Inanother example the laser diode operates with wavelength in the 1100 to2500 nm range based on InP for eye-safe wavelength IR illumination,range finding, LIDAR sensing, and communication could be included. TheIR emitting laser diode could be comprised of compound semiconductormaterials including GaAs, InP, InGaAs, InAs, InAlAs, AlGaAs, AlInGaP,InGaAsP, or InGaAsSb, or some combination thereof. Additionally, the IRemitting laser diode could be based on interband electron-holerecombination such as a quantum well laser-diode, or could be based onquantum cascade laser diode operating with intraband or interbandtransitions. In another example the laser diode operates with wavelengthin the 2500 nm to 15000 nm wavelength range based on quantum cascadelaser technology for mid-IR thermal imaging, sensing, and communicationcould be included. For example, GaInAs/AlInAs quantum cascade lasersoperate at room temperature in the wavelength range of 3 μm to 8 μm. TheIR emitting laser diode is based on an edge-emitting design or avertical cavity emitting design. Optionally, the IR emitting laser diodeis configured with the same surface mount device package with thegallium and nitrogen containing laser device.

Optionally, the at least two color phosphor regions of the wavelengthconverting member include a first phosphor material configured to absorba first ratio of the laser beam with the first peak wavelength in theviolet spectrum and convert to a first color spectrum with a secondwavelength longer than the first peak wavelength to emit the outputlight beam with a first color point, a second phosphor materialconfigured to absorb a second ratio of the laser beam with the firstpeak wavelength in the blue spectrum and convert to a second colorspectrum with a second wavelength longer than the first peak wavelengthto emit the output light beam with a second color point, a thirdphosphor material configured to absorb a third ratio of the laser beamwith the first peak wavelength in the violet or blue spectrum andconvert to a third color spectrum with a second wavelength longer thanthe first peak wavelength to emit the output light beam with a thirdcolor point.

Extending the usable wavelength range for laser-based lighting, it ispossible to use Infrared down-converting phosphors to generate emissionin the NIR (0.7-1.4 um) and mid-IR (1.4-3.0 um) spectrum. This could bepurely Infrared emission, or a combination of visible and infraredemission depending on application requirements. A large number ofpotential IR phosphors exist, but their suitability depends on theapplication wavelength, and the phosphors inherent properties forconversion of visible light to IR light.

Optionally, the portable apparatus with the dynamic light source furtherincludes a second beam shaping optical element configured to collimateand direct the output light beam by at least modifying an angulardistribution thereof. The second beam shaping optical element includesone or a combination of several optical devices including slow axiscollimating lens, fast axis collimating lens, aspheric lens, ball lens,total internal reflector (TIR) optics, parabolic lens optics, refractiveoptics, and micro-electromechanical system (MEMS) mirrors.

Optionally, the beam steering optical element is selected from one of amicro-electromechanical system (MEMS) mirror, a digital light processing(DLP) chip, a digital mirror device (DMD), and a liquid crystal onsilicon (LCOS) chip, a lens, a reflector, a projector, a transmitter, anamplifier for steering, patterning, or pixelating the white-color lightor IR light.

In yet another aspect, the present disclosure provides a portabledynamic light source with color and brightness control for visible lightcommunication. The portable dynamic light source includes a compacthousing with an internal power supply. Optionally, the compact housingis configured to be as small as a handheld module. The portable dynamiclight source also includes a modem disposed in the compact housing andconfigured to receive digital information for communication and alsoincludes multiple drivers/controllers including a laser driverconfigured to generate one or more driving currents and a modulationsignal based on the digital information. Additionally, the portabledynamic light source includes a laser device in surface mount device(SMD) package configured to be driven by the one or more drivingcurrents to emit at lease a first laser beam with a first peakwavelength in a color range of violet or blue spectrum and a secondlaser beam with a second peak wavelength longer than the first peakwavelength. At least one of the first laser beam and the second laserbeam is modulated by the modulation signal to carry the digitalinformation. The portable dynamic light source further includes a beamshaping optical element configured to collimate, focus, and dynamicallydirect the first laser beam and the second laser beam respectivelythrough a pathway. Furthermore, the portable dynamic light sourceincludes a wavelength converting member configured in the SMD package toreceive either the first laser beam or the second laser beam from thepathway and to convert a first fraction of the first laser beam with thefirst peak wavelength to a first spectrum with a third peak wavelengthlonger than the first peak wavelength or convert a second fraction ofthe second laser beam with the second peak wavelength to a secondspectrum with a fourth peak wavelength longer than the second peakwavelength. The first spectrum and the second spectrum respectivelycombine with remaining fraction of the first laser beam with the firstpeak wavelength and the second laser beam with the second peakwavelength to reemit an output light beam of a broader spectrumdynamically varied from a first color point to a second color point. Theportable dynamic light source further includes a beam steering opticalelement disposed near an aperture of the compact housing and configuredto spatially direct the output light beam. Moreover, the multipledrivers/controllers of the portable dynamic light source includes a beamsteering driver configured to generate control signals based on inputinformation for the beam steering optical element to dynamically scanthe output light beam to provide spatially modulated illumination withdynamically varied color point onto one or more of multiple target areasor into one or more of multiple target directions in one or moreselected periods while simultaneously transmit digital information to areceiver in one or more of multiple target areas or one or more ofmultiple target directions in one or more selected periods.

Optionally, the laser device in SMD package is disposed in the compacthousing and includes one or more first laser diodes for emitting thefirst laser beam with the first peak wavelength in violet spectrumranging from 380 to 420 nm or blue spectrum ranging from 420 to 480 nm.The one or more first laser diodes include an active region including agallium and nitrogen containing material configured to be driven by theone or more driving currents. The gallium and nitrogen containingmaterial comprises one or more of GaN, AlN, InN, InGaN, AlGaN, InAlN,InAlGaN.

Optionally, the laser device in SMD package includes one or more secondlaser diodes for emitting the second laser beam with the second peakwavelength in red spectrum ranging from 600 nm to 670 nm, or in greenspectrum ranging from 480 nm to 550 nm, or a blue spectrum with a longerwavelength than that of the first peak wavelength. The one or moresecond laser diodes include an active region including a gallium andarsenic containing material configured to be driven by the one or moredriving currents. Optionally, the laser device in the same SMD packagealso includes a laser diode configured to emit a third laser beam whichis shaped into a directional IR electromagnetic radiation with a thirdpeak wavelength in Infrared frequency range.

Optionally, the directional IR electromagnetic radiation with the thirdpeak wavelength is emitted from a laser diode operating in a range fromabout 700 nm to about 15000 nm. In one example the laser diode operateswith wavelength in the 700 nm to 1100 nm range based on GaAs for near-IRnight vision illumination, range finding and LIDAR sensing, andcommunication could be included. In another example the laser diodeoperates with wavelength in the 1100 to 2500 nm range based on InP foreye-safe wavelength IR illumination, range finding, LIDAR sensing, andcommunication could be included. The IR emitting laser diode could becomprised of compound semiconductor materials including GaAs, InP,InGaAs, InAs, InAlAs, AlGaAs, AlInGaP, InGaAsP, or InGaAsSb, or somecombination thereof. Additionally, the IR emitting laser diode could bebased on interband electron-hole recombination such as a quantum welllaser diode, or could be based on quantum cascade laser diode operatingwith intraband or interband transitions. In another example the laserdiode operates with wavelength in the 2500 nm to 15000 nm wavelengthrange based on quantum cascade laser technology for mid-IR thermalimaging, sensing, and communication could be included. For example,GaInAs/AlInAs quantum cascade lasers operate at room temperature in thewavelength range of 3 nm to 8 nm. The IR emitting laser diode is basedon an edge-emitting design or a vertical cavity emitting design.

Optionally, the first laser, second, and/or third laser beams areindependently modulated by the modulation signal to act as independentchannels to communicate the digital information.

Optionally, the wavelength converting member includes a first phosphormaterial selected for absorbing a first ratio of the first laser beamwith the first peak wavelength in the violet spectrum and converting toa first spectrum with a second wavelength longer than the first peakwavelength to emit a first output light beam with a first color point, asecond phosphor material selected for absorbing partially second ratioof the first laser beam with the first peak wavelength in the bluespectrum and converting to a second spectrum with a second wavelengthlonger than the first peak wavelength to emit a second output light beamwith a second color point, a third phosphor material selected forabsorbing a third ratio of the second laser beam with the first peakwavelength in the red spectrum and converting to a third spectrum with asecond wavelength longer than the first peak wavelength to emit a thirdoutput light beam with a third color point.

Optionally, the beam shaping optical element includes one or acombination of more optical elements selected a list of slow axiscollimating lens, fast axis collimating lens, aspheric lens, ball lens,total internal reflector (TIR) optics, parabolic lens optics, refractiveoptics, and micro-electromechanical system (MEMS) mirrors configured todirect, collimate, focus each of the first laser beam and second laserbeam with modified angular distributions as incident beams intocorresponding first, second, third phosphor material for tuning thefirst, second, third ratio of the first and second laser beams beingconverted thereof for dynamically adjusting the first, second, thirdcolor point of the respective first, second, third output light beam.

Optionally, the beam steering optical element includes one of amicro-electromechanical system (MEMS) mirror, a digital light processing(DLP) chip, a digital mirror device (DMD), and a liquid crystal onsilicon (LCOS) chip, a lens, a reflector, a projector, a transmitter, anamplifier for steering, patterning, or pixelating the white-color lightor IR light.

In another embodiment, the present invention provides gallium andnitrogen laser based illumination sources integrated with IRillumination sources coupled to one or more sensors with a feedback loopor control circuitry to trigger the light source to react with one ormore predetermined responses such as activating the visible lightemission for a visible light illumination, activating IR light emissionfor an IR illumination, activating a VLC signal or dynamic spatialpatterning of light, a light movement response, a light color response,a light brightness response, a spatial light pattern response, otherresponse, or a combination of responses. Specific embodiments of thisinvention employ a transferred gallium and nitrogen containing materialprocess for fabricating laser diodes or other gallium and nitrogencontaining devices enabling benefits over conventional fabricationtechnologies.

In yet still another aspect, the present disclosure describes alaser-based light source integrated with an IR illumination sourcewithin a portable housing to form a compact smart light sourceconfigured for visible/IR light communication. The compact smart lightsource includes a controller comprising a modem and one or more driversdisposed on a printed circuit board assembly integrated within theportable housing and powered by an internal power supply. The modem isconfigured to receive data signal and operate the driver to generate adriving current and a modulation signal. Optionally, the internal powersupply is a compact high capacity battery. Additionally, the compactsmart light source includes a light emitter configured as a pump-lightdevice comprised of a gallium and nitrogen containing material and anoptical cavity comprising an optical waveguide region and one or morefacet regions. The optical cavity is configured with electrodes tosupply the driving current from one of the one or more drivers to thegallium and nitrogen containing material to provide optical gain to anelectromagnetic radiation propagating in the optical waveguide regionand output a directional electromagnetic radiation through at least oneof the one or more facet regions. The directional electromagneticradiation is characterized by a first peak wavelength in theultra-violet or blue wavelength regime and modulated to carry the datasignal using the modulation signal by the controller. Optionally, thecompact smart light source includes a light emitter configured as anIR-emitting laser diode configured to output a directional IRelectromagnetic radiation which is also optionally modulated to carrycommunication signal. The compact smart light source further includes awavelength converter optically coupled to the directionalelectromagnetic radiation from the pump-light device, wherein thewavelength converter is configured to convert at least a fraction of thedirectional electromagnetic radiation with the first peak wavelength toat least a second peak wavelength that is longer than the first peakwavelength and to output a white-color spectrum comprising at least thesecond peak wavelength and partially the first peak wavelength.Furthermore, the compact smart light source includes a beam shaperconfigured to collimate and focus a beam of the white-color spectrum toa certain direction or a certain focal point. The compact smart lightsource further includes a beam steering element driven by one of the oneor more drivers to manipulate the beam of the white-color spectrum andoptionally the IR radiation for illuminating a target of interest andtransmitting the data signal through at least the fraction of thedirectional electromagnetic radiation with the first peak wavelength toa visible light receiver or an IR light receiver at the target ofinterest. Moreover, the compact smart light source includes one or moresensors or detectors being configured in a feedback loop circuit coupledto the controller. The one or more sensors or detectors are driven byone of the one or more drivers to provide one or more feedback currentsor voltages based on the various parameters associated with the targetof interest detected in real time to the controller with one or more oflight movement response, light color response, light brightnessresponse, spatial light pattern response, and data signal communicationresponse being triggered.

Optionally, the wavelength converter includes a phosphor materialconfigured as in a reflection mode to have a surface receiving thedirectional electromagnetic radiation in an incident angle. Thewhite-color spectrum is a combination of a spectrum of the second peakwavelength converted by the phosphor material, a fraction of thedirectional electromagnetic radiation with the first peak wavelengthreflected from the surface of the phosphor material, and a fraction ofthe directional electromagnetic radiation scattered from interior of thephosphor material.

Optionally, the wavelength converter includes a phosphor materialconfigured as in a transmission mode to receive the directionalelectromagnetic radiation passed through. The white-color spectrum is acombination of a fraction of the directional electromagnetic radiationnot absorbed by the phosphor material and a spectrum of the second peakwavelength converted by the phosphor material.

Optionally, the wavelength converter includes a plurality of wavelengthconverting regions that respectively convert blue or violet wavelengthregime to a predominantly red spectrum, or a predominantly greenspectrum, and/or a predominantly blue spectrum with a longer peakwavelength than the first peak wavelength of the directionalelectromagnetic radiation.

Optionally, the beam steering element includes a plurality ofcolor-specific optical elements for independently manipulating thepredominantly red spectrum, the predominantly green spectrum, and thepredominantly blue spectrum for transmitting to different targets ofinterests carrying different streams of the data signal for differentreceivers.

Optionally, the beam steering element is configured to manipulate anddirect the beam of the white-color spectrum and optionally the beam ofIR radiation as an illumination source with spatial modulation forilluminating a surface at the target of interest along a preferreddirection.

Optionally, the beam steering element further is configured to directthe white-color spectrum and optionally the IR radiation for dynamicallyscanning a spatial range around the target of interest.

Optionally, the one or more sensors include one or a combination ofmultiple of sensors or detectors selected from microphone, geophone,motion sensor, radio-frequency identification (RFID) receivers,hydrophone, chemical sensors including a hydrogen sensor, CO₂ sensor, orelectronic nose sensor, flow sensor, water meter, gas meter, Geigercounter, altimeter, airspeed sensor, speed sensor, range finder,piezoelectric sensor, gyroscope, inertial sensor, accelerometer, MEMSsensor, Hall effect sensor, metal detector, voltage detector,photoelectric sensor, photodetector, photoresistor, pressure sensor,strain gauge, thermistor, thermocouple, pyrometer, temperature gauge,motion detector, passive infrared sensor, Doppler sensor, biosensor,capacitance sensor, video cameras, transducer, image sensor, infraredsensor, radar, SONAR, LIDAR.

Optionally, the one or more sensors or detectors is configured in thefeedback loop circuit to provide a feedback current or voltage to tune acontrol signal for operating the driver to adjust brightness and colorof the directional electromagnetic radiation from the light-emitter.

Optionally, the one or more sensors or detectors is configured in thefeedback loop circuit to provide a feedback current or voltage to tune acontrol signal for operating the beam steering optical element to adjusta spatial position and pattern illuminated by the beam of thewhite-color spectrum.

Optionally, the one or more sensors or detectors is configured in thefeedback loop circuit to send a feedback current or voltage back to thecontroller to change the driving current and the modulation signal forchanging the data signal to be communicated through at least a fractionof the directional electromagnetic radiation modulated by the modulationsignal.

Optionally, the controller further is configured to provide controlsignals to tune the beam shaper for dynamically modulating thewhite-color spectrum based on feedback from the one or more sensors ordetectors.

Optionally, the controller is a microprocessor embedded within theportable housing. Optionally, the controller is disposed in a smartphone, a smart watch, a computerized wearable device, a tablet computer,a laptop computer, a vehicle-built-in computer, a drone and remotelylinked to the compact smart light source wirelessly.

Optionally, the beam steering element further is configured toindependently transmit the data signal to different receivers indifferent direction in different period synchronized with the spatialmodulation of the white-color spectrum or IR radiation illuminated intothe particular direction.

Optionally, the beam steering element includes an optical deviceselected from one of a micro-electromechanical system (MEMS) mirror, adigital light processing (DLP) chip, a digital mirror device (DMD), anda liquid crystal on silicon (LCOS) chip for steering, patterning, orpixelating the white-color spectrum or infrared spectrum.

Optionally, the MEMS mirror is configured to produce high deflectionangles more than 10 degrees, low in power consumption of less than 100mW, and high scan frequencies capable of producing HD resolution.

Optionally, the MEMS mirror is configured to perform resonant operationfor vector pointing and provide high reflectivity of >80% for high poweroperation.

Optionally, the beam steering element includes a 2-dimensional array ofmicro-mirrors to steer, pattern, and/or pixelate a beam of thewhite-color light by reflecting from corresponding pixels at apredetermined angle to turn each pixel on or off.

Optionally, the 2-dimensional array of micro-mirrors is formed on asilicon chip configured for providing dynamic spatial modulation of thebeam of white-color spectrum.

Optionally, the beam steering element further is configured to spatiallymodulate and dynamically direct the white-color light or Infrared lightbased on the input information to provide spatially modulatedillumination onto a first area of a target surface or into firstdirection of a target space in a first period and onto a second area ofthe target surface or into a second direction of a target space in asecond period, and to independently transmit the data signals to a firstreceiver at the first area or downstream in the first direction in thefirst period and to a second receiver at the second area or downstreamin the second direction in the second period.

Optionally, each of the first receiver and the second receiver comprisesa photodiode, avalanche photodiode, photomultiplier tube, and one ormore band-pass filters to detect pulse-modulated light signals, and iscoupled to a modem configured to decode the light signals into binarydata.

In yet still another aspect, the present disclosure provides a smartlight source with spatial illumination and color dynamic control in aportable or handheld module package. The smart light source includes amicrocontroller for generating one or more control signals and a laserdevice configured to be driven by at least one of the one or morecontrol signals to emit a laser beam with a first peak wavelength in acolor range of violet or blue spectrum. The laser beam is modulated bythe at least one modulation signal to carry the digital information.Additionally, the smart light source includes a beam shaping opticalelement configured to dynamically direct the laser beam with a varyingangle through an aperture into a pathway. The smart light source furtherincludes a wavelength converting member comprising at least two colorphosphor regions spatially distributed to respectively receive the laserbeam with different angle outputted from the pathway and configured toconvert a fraction of the laser beam with the first peak wavelength toat least two color spectra respectively by the at least two colorphosphor regions. Each of the at least two color spectra includes asecond peak wavelength longer than the first peak wavelength but varyingwith the fraction of the laser beam being absorbed by each of the atleast two color phosphor regions. The at least two color spectra arerespectively combined with remaining fraction of the laser beam with thefirst peak wavelength to reemit an output light beam of a broaderspectrum with a dynamically varied color point. Furthermore, the smartlight source includes a beam steering optical element configured tospatially direct the output light beam. Moreover, the light sourceincludes a beam steering driver coupled to the microcontroller toreceive some of the one or more control signals based on inputinformation for the beam steering optical element to dynamically scanthe output light beam substantially in white color to provide spatiallymodulated illumination and selectively direct one or more of themultiple laser beams with the first peak wavelengths in different colorranges onto one or more of multiple target areas or into one or more ofmultiple target directions in one or more selected periods. Optionally,the microcontroller is disposed on a printed circuit board assemblypowered by a compact internal power supply inside a handheld-typehousing. Optionally, the handheld-type housing has an aperture where thebeam steering optical element is installed for scanning the light beamin white color.

In yet still an alternative aspect, the present disclosure provides asmart light source with spatially modulated illumination configuredwithin a handheld-type package powered by a compact high capacitybattery. The smart light source includes a controller configured toreceive input information for generating one or more control signals.Optionally, the controller is installed on a printed circuit boardassembly enclosed with the handheld-type package. The smart light sourcefurther includes a light emitter configured as a pump-light devicecomprised of a gallium and nitrogen containing material and an opticalcavity; the optical cavity comprising an optical waveguide region andone or more facet regions. The optical cavity is configured withelectrodes to supply a driving current based on at least one of the oneor more control signals to the gallium and nitrogen containing material.The driving current provides an optical gain to an electromagneticradiation propagating in the optical waveguide region. Theelectromagnetic radiation is outputted through at least one of the oneor more facet regions as a directional electromagnetic radiationcharacterized by a first peak wavelength in the ultra-violet or bluewavelength regime. Furthermore, the smart light source includes a beamshaper configured to collimate and focus the directional electromagneticradiation to a certain direction and focal point and a wavelengthconverter optically coupled to the directional electromagnetic radiationfrom the pump-light device. The wavelength converter is configured toabsorb at least a fraction of the directional electromagnetic radiationwith the first peak wavelength to excite a spectrum with a second peakwavelength that is longer than the first peak wavelength and to reemitan output electromagnetic radiation with a broader spectrum comprisingat least the second peak wavelength and partially the first peakwavelength. The smart light source further includes a beam steeringoptical element configured near an aperture region of the handheld-typepackage to manipulate the output electromagnetic radiation for providingspatially modulated illuminations through the aperture onto a targetarea or into a target direction. Moreover, the smart light sourceincludes one or more sensors being configured also near the apertureregion in a feedback loop circuit coupled to the controller. The one ormore sensors are configured to provide one or more feedback currents orvoltages based on the various parameters associated with the target ofinterest detected in real time to the controller with one or more oflight movement response, light color response, light brightnessresponse, spatial light pattern response, and data signal communicationresponse being triggered.

In yet still another alternative aspect, the present disclosure providesa smart light system with color and brightness dynamic controlconfigured in a portable package convenient designed for fielddeployment by individual user. Optionally, the portable package issimilar to a handheld flashlight or spotlight like module. The smartlight system includes a microcontroller configured to receive inputinformation for generating one or more control signals. Optionally, themicrocontroller is disposed on a printed circuit board assembled insidethe portable package and powered by a compact high capacity battery. Acharging port is provided with the portable package. An interface fordata communication or user input is also provided with the portablepackage. Additionally, the smart light system includes a laser deviceconfigured to be driven by at least one of the one or more controlsignals to emit at lease a first laser beam with a first peak wavelengthin a color range of violet or blue spectrum and a second laser beam witha second peak wavelength longer than the first peak wavelength. Thesmart light system further includes a pathway configured to dynamicallyguide the first laser beam and the second laser beam. Furthermore, thesmart light system includes a wavelength converting member configured toreceive either the first laser beam or the second laser beam from thepathway and configured to convert a first fraction of the first laserbeam with the first peak wavelength to a first spectrum with a thirdpeak wavelength longer than the first peak wavelength or convert asecond fraction of the second laser beam with the second peak wavelengthto a second spectrum with a fourth peak wavelength longer than thesecond peak wavelength. The first spectrum and the second spectrumrespectively combine with remaining fraction of the first laser beamwith the first peak wavelength and the second laser beam with the secondpeak wavelength to reemit an output light beam of a broader spectrumdynamically varied from a first color point to a second color point. Thesmart light system includes a beam shaping optical element configured tocollimate and focus the output light beam and a beam steering opticalelement configured to direct the output light beam. Moreover, the smartlight system includes a beam steering driver coupled to themicrocontroller to receive some of the one or more control signals basedon input information for the beam steering optical element todynamically scan the output light beam substantially in white color toprovide spatially modulated illumination and selectively direct one ormore of the multiple laser beams with the first peak wavelengths indifferent color ranges onto one or more of multiple target areas or intoone or more of multiple target directions in one or more selectedperiods. Optionally, the beam steering driver is also disposed on theprinted circuit board assembly. Optionally, the beam steering opticalelement is disposed near an aperture of the portable package to deliverthe output light beam with spatially modulation to target of interest.Even further, the smart light system includes one or more sensors beingconfigured in a feedback loop circuit coupled to the controller. The oneor more sensors are configured also near the aperture to detect thelight signals returned from the target of interest and convert to one ormore feedback currents or voltages in real time sent to the controllerwith one or more of light movement response, light color response, lightbrightness response, spatial light pattern response, and data signalcommunication response being triggered.

Merely by way of example, the present invention can be applied toapplications such as white lighting, white spot lighting, flash lights,automobile headlights, all-terrain vehicle lighting, light sources usedin recreational sports such as biking, surfing, running, racing,boating, light sources used for drones, planes, robots, other mobile orrobotic applications, safety, counter measures in defense applications,multi-colored lighting, lighting for flat panels, medical, metrology,beam projectors and other displays, high intensity lamps, spectroscopy,entertainment, theater, music, and concerts, analysis fraud detectionand/or authenticating, tools, water treatment, laser dazzlers,targeting, communications, LiFi, visible light communications (VLC),sensing, detecting, distance detecting, Light Detection And Ranging(LIDAR), transformations, transportations, leveling, curing and otherchemical treatments, heating, cutting and/or ablating, pumping otheroptical devices, other optoelectronic devices and related applications,and source lighting and the like. The integrated light source accordingto this invention can be incorporated into an automotive headlight, ageneral illumination source, a security light source, a search lightsource, a defense light source, as a light fidelity (LiFi) communicationdevice, for horticulture purposes to optimize plant growth, or manyother applications.

BRIEF DESCRIPTION OF THE FIGURES

The following drawings are merely examples for illustrative purposesaccording to various disclosed embodiments and are not intended to limitthe scope of the present invention.

FIG. 1 is a schematic diagram showing dependence of internal quantumefficiency in a laser diode on carrier concentration in the lightemitting layers of the device.

FIG. 2 is a plot of external quantum efficiency as a function of currentdensity for a high power blue laser diode compared to the high powerblue light emitting diode.

FIG. 3 is a simplified schematic diagram of a laser diode formed on agallium and nitrogen containing substrate with the cavity aligned in adirection ended with cleaved or etched mirrors according to someembodiments of the present invention.

FIG. 4 is a cross-sectional view of a laser device according to anembodiment of the present invention.

FIG. 5 is a schematic diagram illustrating a chip on submount (CoS)based on a conventional laser diode formed on gallium and nitrogencontaining substrate technology according to an embodiment of thepresent invention.

FIG. 6 is a schematic diagram illustrating a process comprised of firstforming the bond between an epitaxial material formed on the gallium andnitrogen containing substrate and then subjecting a sacrificial releasematerial to the PEC etch process to release the gallium and nitrogencontaining substrate according to some embodiments of the presentinvention.

FIG. 7 is a schematic representation of the die expansion process withselective area bonding according to some embodiments of the presentinvention.

FIG. 8 is an example of a processed laser diode cross-section accordingto an embodiment of the present invention.

FIG. 9 is a schematic diagram illustrating a CoS based on lifted off andtransferred epitaxial gallium and nitrogen containing layers accordingto an embodiment of this present invention.

FIG. 10A is a functional block diagram for a laser-based white lightsource integrated with an IR illumination source containing a UV or bluepump laser, a visible wavelength converting element, and an IR emittinglaser diode according to an embodiment of the present invention.

FIG. 10B is a functional block diagram for a laser-based white lightsource integrated with an IR illumination source containing a UV or bluepump laser, a visible emitting phosphor member, and an IR emitting laserdiode according to an embodiment of the present invention.

FIG. 10C is an example optical spectrum of a laser based white lightsource configured with an IR emitting laser diode for IR illuminationaccording to an embodiment of the present invention.

FIG. 11A is a schematic diagram of a single crystal IR emitting phosphorconfigured for reflection mode operation according to an embodiment ofthe present invention.

FIG. 11B is a schematic diagram of an IR emitting phosphor in glassmember configured for reflection mode operation according to anembodiment of the present invention.

FIG. 11C is a schematic diagram of a sintered powder or ceramic IRemitting phosphor configured for reflection mode operation according toan embodiment of the present invention.

FIG. 12A is a functional block diagram for a laser-based white lightsource integrated with an IR illumination source containing a UV or bluepump laser, a red or near-IR emitting laser diode, a visible lightemitting phosphor member, and a IR emitting phosphor member according toan embodiment of the present invention.

FIG. 12B is a functional block diagram for a laser-based white lightsource integrated with an IR illumination source containing a UV or bluepump laser diode, a beam steering element, a visible light emittingphosphor member, and an IR emitting phosphor member according to anembodiment of the present invention.

FIG. 13A is a schematic diagram of a stacked phosphor member comprisedof a visible light emitting phosphor and an IR emitting phosphorconfigured for reflection mode operation according to an embodiment ofthe present invention.

FIG. 13B is a schematic diagram of a composite phosphor member comprisedof visible light emitting phosphor elements and IR emitting phosphorelements combined into a common volume region and configured forreflection mode operation according to an embodiment of the presentinvention.

FIG. 14A is a functional block diagram for a laser-based white lightsource integrated with an IR illumination source containing a UV or bluepump laser diode and a phosphor member configured for both visible lightemission and IR emission according to an embodiment of the presentinvention.

FIG. 14B is an example optical spectrum of a laser based white lightsource configured with an IR emitting wavelength converter to provide anIR illumination according to an embodiment of the present invention.

FIG. 15A is a functional block diagram for a laser-based white lightsource integrated with an IR illumination source containing a UV or bluepump laser, a red or near-IR emitting laser diode, and a phosphor memberconfigured for both visible light emission and IR emission according toan embodiment of the present invention.

FIG. 15B is an example optical spectrum of a laser based white lightsource configured with a red or near IR emitting laser diode to excitean IR emitting wavelength converter to provide an IR illuminationaccording to an embodiment of the present invention.

FIG. 16A is a schematic diagram of a laser based white light source withan IR illumination capability operating in transmission mode and housedin a TO canister style package according to an embodiment of the presentinvention.

FIG. 16B is a side view schematic diagram of a laser based white lightsource with an IR illumination capability operating in transmission modeand housed in a TO canister style package with an IR emitting wavelengthconverter member configured with the transparent window of the capaccording to an embodiment of the present invention.

FIG. 16C is a side view schematic diagram of a laser based white lightsource with an IR illumination capability operating in transmission modeand housed in a TO canister style package with an IR and visible lightemitting based wavelength converter member configured with thetransparent window of the cap according to an embodiment of the presentinvention.

FIG. 16D is a side view schematic diagram of an IR and visible lightemitting based wavelength converter member configured with thetransparent window of the cap according to an embodiment of the presentinvention.

FIG. 16E is a schematic diagram of a laser based white light sourceoperating in reflection mode and housed in a TO canister style packageaccording to another embodiment of the present invention.

FIG. 17A is a schematic diagram of a laser based white light source withan IR illumination capability operating in reflection mode according toan embodiment of the present invention.

FIG. 17B is a schematic diagram of a laser based white light source withan IR illumination capability operating in reflection mode according toan embodiment of the present invention.

FIG. 18A is a schematic diagram of a laser based white light source withan IR illumination capability operating in reflection mode in a surfacemount package according to an embodiment of the present invention.

FIG. 18B is a schematic diagram of a laser based white light source withan IR illumination capability operating in reflection mode in a surfacemount package according to another embodiment of the present invention.

FIG. 18C is a schematic diagram of a laser based white light source withan IR illumination capability operating with side-pumped phosphor in asurface mount package according to another embodiment of the presentinvention.

FIG. 19A is a side-view schematic diagram of a laser based white lightsource with an IR illumination capability operating in reflection modein an enclosed surface mount package according to an embodiment of thepresent invention.

FIG. 19B is a side-view schematic diagram of a fiber-coupled laser basedwhite light source with an IR illumination capability operating inreflection mode in an enclosed package according to an embodiment of thepresent invention.

FIG. 20 is a functional block diagram for a laser-based white lightsource integrated with an IR illumination source containing a UV or bluepump laser, a visible wavelength converting element, an IR emittinglaser diode, and sensor members configured for illumination activationbased on sensor feedback according to an embodiment of the presentinvention.

FIG. 21A is a functional block diagram of a laser based white lightsource enabled for visible light communication according to anembodiment of the present invention.

FIG. 21B is a functional block diagram of a laser based white lightsource enabled for visible light communication according to anotherembodiment of the present invention.

FIG. 22A is a functional block diagram for a laser-based smart-lightingsystem according to some embodiments of the present invention.

FIG. 22B is a functional diagram for a dynamic, laser-basedsmart-lighting system according to some embodiments of the presentinvention.

FIG. 23A is a schematic diagram of an apparatus comprising both a depthsensing system and laser based visible light source according to someembodiments of the present invention.

FIG. 23B is a simplified schematic diagram of a laser light illuminationsystem integrated with a depth sensing system according to someembodiments of the present invention.

FIG. 23C is a simplified schematic diagram of a laser light illuminationsystem integrated with a depth sensing system according to somealternative embodiments of the present invention.

FIG. 23D is a simplified schematic diagram of a combination of GaNcontaining laser light and IR-emitting laser illumination systemintegrated with a depth sensing system according to another alternativeembodiment of the present invention.

FIG. 23E is a simplified schematic diagram of a combination of GaNcontaining laser light and/or IR-emitting laser illumination systemintegrated with a depth sensing system according to yet anotheralternative embodiment of the present invention.

FIG. 23F is a simplified schematic diagram of a combination of GaNcontaining laser light and/or IR-emitting laser illumination systemintegrated with a depth sensing system according to still anotheralternative embodiment of the present invention.

FIG. 23G is a simplified schematic diagram of a combination of GaNcontaining laser light and IR-emitting laser illumination systemintegrated with a data communication system according to yet anotherembodiment of the present invention.

FIG. 23H is a simplified schematic diagram of a combination of GaNcontaining laser light and IR-emitting laser illumination systemintegrated with a data communication system according to still anotherembodiment of the present invention.

FIG. 24 is a cross-section diagram of a compact package of smartvisible/infrared light device configured with a gallium and nitrogencontaining laser source according to some embodiments of the presentinvention.

FIG. 25 is a simplified diagram of an attachable lighting moduleconfigured for visible-light/infrared light illumination, depth sensing,and communication according to some embodiments of the presentinvention.

DETAILED DESCRIPTION

The present invention provides a portable apparatus configured with awhite-light and/or an infrared (IR) illumination source based on agallium and nitrogen containing laser diodes in surface mount devices.With the capability to emit light in both the visible spectrum and theinfrared spectrum, the portable apparatus is optionally a dual-bandemitting light source with either or both being applied for distanceranging and/or light communication. In some embodiments the gallium andnitrogen containing laser diode is fabricated with a process to transfergallium and nitrogen containing layers and methods of manufacture anduse thereof. In some embodiments, the portable apparatus includes ahousing that is configured to be a compact, portable, or handheldpackage containing controller/drivers, transmitters, andsensors/detectors to form feedback loops that can activate the infraredillumination source and/or the laser-based white light illuminationsource, modulate the light signals transmitted out of these sourcesbased on certain input data, and detect light signals returned fromfield for various applications. Merely by examples, the inventionprovides integrated smart laser lighting devices and methods, configuredwith infrared and visible illumination capability for spotlighting,detection, imaging, projection display, spatially dynamic lightingdevices and methods, depth finding, infrared surveying, andvisible/infrared light communication devices and methods, and variouscombinations of above in applications of general lighting, commerciallighting and display, automotive lighting and communication, defense andsecurity, search and rescue, industrial processing, internetcommunications, agriculture or horticulture. The portable integratedlight source according to this invention can be miniaturized toincorporate those functions into a flashlight, a hand-held illuminationsource or security light source or a search light source or a defenselight source, as well as a light fidelity (LiFi) communication device ora device for horticulture purposes to optimize plant growth, or manyother applications.

In an aspect, this invention provides novel uses and configurations ofgallium and nitrogen containing laser diodes in lighting systemsconfigured for IR illumination, which can be deployed in dual spectrumspotlighting, imaging, sensing, and searching applications. Configuredwith a laser based white light source and an IR light source, thisinvention is capable of emitting light both in the visible wavelengthband and in the IR wavelength band, and is configured to selectivelyoperate in one band or simultaneously in both bands. This dual bandemission source can be deployed in communication systems such as visiblelight communication systems such as Li-Fi systems, communications usingthe convergence of lighting and display with static or dynamic spatialpatterning using beam shaping elements such as MEMS scanning mirrors ordigital light processing units, and communications triggered byintegrated sensor feedback. Specific embodiments of this inventionemploy a transferred gallium and nitrogen containing material processfor fabricating laser diodes or other gallium and nitrogen containingdevices enabling benefits over conventional fabrication technologies.

The present invention is configured for both visible light emission andIR light emission. While the necessity and utility of visible light isclearly understood, it is often desirable to provide illuminationwavelength bands that are not visible. In one example, IR illuminationis used for night vision. Night vision or IR detection devices play acritical role in defense, security, search and rescue, and recreationalactivities in both the private sector and at the municipal or governmentsectors. By providing the ability to see in no or low ambient lightconditions, night vision technology is widely deployed to the consumermarkets for several applications including hunting, gaming, driving,locating, detecting, personal protection, and others. Whether bybiological or technological means, night vision and IR detection aremade possible by a combination of sufficient spectral range andsufficient intensity range. Such detection can be for two-dimensionalimaging, or three-dimensional distance measurement such asrange-finding, or three-dimensional imaging such as LIDAR.

As background, while LED-based light sources offer great advantages overincandescent based sources, there are still challenges and limitationsassociated with LED device physics. The first limitation is the socalled “droop” phenomenon that plagues GaN based LEDs. The droop effectleads to power rollover with increased current density, which forcesLEDs to hit peak external quantum efficiency at very low currentdensities in the 10-200 A/cm² range. FIG. 1 shows a schematic diagram ofthe relationship between internal quantum efficiency (IQE) and carrierconcentration in the light emitting layers of a light emitting diode(LED) and light-emitting devices where stimulated emission issignificant such as laser diodes (LDs) or super-luminescent LEDs. IQE isdefined as the ratio of the radiative recombination rate to the totalrecombination rate in the device. At low carrier concentrationsShockley-Reed-Hall recombination at crystal defects dominatesrecombination rates such that IQE is low. At moderate carrierconcentrations, spontaneous radiative recombination dominates such thatIQE is relatively high. At high carrier concentrations, non-radiativeauger recombination dominates such that IQE is again relatively low. Indevices such as LDs or SLEDs, stimulated emission at very high carrierdensities leads to a fourth regime where IQE is relatively high. FIG. 2shows a plot of the external quantum efficiency (EQE) for a typical blueLED and for a high-power blue laser diode. EQE is defined as the productof the IQE and the fraction of generated photons that are able to exitthe device. While the blue LED achieves a very high EQE at very lowcurrent densities, it exhibits very low EQE at high current densitiesdue to the dominance of auger recombination at high current densities.The LD, however, is dominated by stimulated emission at high currentdensities, and exhibits very high EQE. At low current densities, the LDhas relatively poor EQE due to reabsorption of photons in the device.Thus, to maximize efficiency of the LED based light source, the currentdensity must be limited to low values where the light output is alsolimited. The result is low output power per unit area of LED die (flux),which forces the use large LED die areas to meet the brightnessrequirements for most applications. For example, a typical LED basedlight bulb will require 3 mm² to 30 mm² of epi area.

A second limitation of LEDs is also related to their brightness, morespecifically it is related to their spatial brightness. A conventionalhigh brightness LED emits ˜1 W per mm² of epi area. With some advancesand breakthrough this can be increased up to 5-10× to 5-10 W per mm² ofepi area. Finally, LEDs fabricated on conventional c-plane GaN sufferfrom strong internal polarization fields, which spatially separate theelectron and hole wave functions and lead to poor radiativerecombination efficiency. Since this phenomenon becomes more pronouncedin InGaN layers with increased indium content for increased wavelengthemission, extending the performance of UV or blue GaN-based LEDs to theblue-green or green regime has been difficult.

An exciting new class of solid-state lighting based on laser diodes israpidly emerging. Like an LED, a laser diode is a two-lead semiconductorlight source that that emits electromagnetic radiation. However, unlikethe output from an LED that is primarily spontaneous emission, theoutput of a laser diode is comprised primarily of stimulated emission.The laser diode contains a gain medium that functions to provideemission through the recombination of electron-hole pairs and a cavityregion that functions as a resonator for the emission from the gainmedium. When a suitable voltage is applied to the leads to sufficientlypump the gain medium, the cavity losses are overcome by the gain and thelaser diode reaches the so-called threshold condition, wherein a steepincrease in the light output versus current input characteristic isobserved. At the threshold condition, the carrier density clamps andstimulated emission dominates the emission. Since the droop phenomenonthat plagues LEDs is dependent on carrier density, the clamped carrierdensity within laser diodes provides a solution to the droop challenge.Further, laser diodes emit highly directional and coherent light withorders of magnitude higher spatial brightness than LEDs. For example, acommercially available edge emitting GaN-based laser diode can reliablyproduce about 2 W of power in an aperture that is 15 μm wide by about0.5 μm tall, which equates to over 250,000 W/mm². This spatialbrightness is over 5 orders of magnitude higher than LEDs or put anotherway, 10,000 times brighter than an LED.

Based on essentially all the pioneering work on GaN LEDs, visible laserdiodes based on GaN technology have rapidly emerged over the past 20years. Currently the only viable direct blue and green laser diodestructures are fabricated from the wurtzite AlGaInN material system. Themanufacturing of light emitting diodes from GaN related materials isdominated by the heteroepitaxial growth of GaN on foreign substratessuch as Si, SiC and sapphire. Laser diode devices operate at such highcurrent densities that the crystalline defects associated withheteroepitaxial growth are not acceptable. Because of this, very lowdefect-density, free-standing GaN substrates have become the substrateof choice for GaN laser diode manufacturing. Unfortunately, such bulkGaN substrates are costly and not widely available in large diameters.For example, 2″ diameter is the most common laser-quality bulk GaNc-plane substrate size today with recent progress enabling 4″ diameter,which are still relatively small compared to the 6″ and greaterdiameters that are commercially available for mature substratetechnologies. Further details of the present invention can be foundthroughout the present specification and more particularly below.

Additional benefits are achieved over pre-existing techniques using thepresent invention. In particular, the present invention enables acost-effective white light source. In a specific embodiment, the presentoptical device can be manufactured in a relatively simple andcost-effective manner. Depending upon the embodiment, the presentapparatus and method can be manufactured using conventional materialsand/or methods according to one of ordinary skill in the art. In someembodiments of this invention the gallium and nitrogen containing laserdiode source is based on c-plane gallium nitride material and in otherembodiments the laser diode is based on nonpolar or semipolar galliumand nitride material. In one embodiment the white source is configuredfrom a chip on submount (CoS) with an integrated phosphor on thesubmount to form a chip and phosphor on submount (CPoS) white lightsource. In some embodiments intermediate submount members may beincluded. In some embodiments the laser diode and the phosphor memberare supported by a common support member such as a package base. In thisembodiment there could be submount members or additional support membersincluded between the laser diode and the common support member.Similarly, there could be submount members or additional support membersincluded between the phosphor member and the common support member.

In various embodiments, the laser device and phosphor device areco-packaged or mounted on a common support member with or withoutintermediate submounts and the phosphor materials are operated in atransmissive mode, a reflective mode, or a side-pumped mode to result ina white emitting laser-based light source. In additional variousembodiments, the electromagnetic radiation from the laser device isremotely coupled to the phosphor device through means such as free spacecoupling or coupling with a waveguide such as a fiber optic cable orother solid waveguiding material, and wherein the phosphor materials areoperated in a transmissive mode, a reflective mode, or a side-pumpedmode to result in a white emitting laser-based light source. Merely byway of example, the invention can be applied to applications such aswhite lighting, white spot lighting, flash lights, automobileheadlights, all-terrain vehicle lighting, flash sources such as cameraflashes, light sources used in recreational sports such as biking,surfing, running, racing, boating, light sources used for drones,planes, robots, other mobile or robotic applications, safety, search andrescue, sensing, range finding, counter measures in defenseapplications, multi-colored lighting, lighting for flat panels, medical,metrology, beam projectors and other displays, high intensity lamps,spectroscopy, entertainment, theater, music, and concerts, analysisfraud detection and/or authenticating, tools, water treatment, laserdazzlers, targeting, communications, LiFi, visible light communications(VLC), sensing, detecting, distance detecting, Light Detection AndRanging (LIDAR), transformations, transportations, leveling, curing andother chemical treatments, heating, cutting and/or ablating, pumpingother optical devices, other optoelectronic devices and relatedapplications, and source lighting and the like.

Laser diodes are ideal as phosphor excitation sources. With a spatialbrightness (optical intensity per unit area) greater than 10,000 timeshigher than conventional LEDs and the extreme directionality of thelaser emission, laser diodes enable characteristics unachievable by LEDsand other light sources. Specifically, since the laser diodes outputbeams carrying over 1 W, over 5 W, over 10 W, or even over 100 W can befocused to very small spot sizes of less than 1 mm in diameter, lessthan 500 μm in diameter, less than 100 μm in diameter, or even less than50 μm in diameter, power densities of over 1 W/mm², 100 W/mm², or evenover 2,500 W/mm² can be achieved. When this very small and powerful beamof laser excitation light is incident on a phosphor material theultimate point source of white light can be achieved. Assuming aphosphor conversion ratio of 200 lumens of emitted white light peroptical watt of excitation light, a 5 W excitation power could generate1000 lumens in a beam diameter of 100 μm, or 50 μm, or less. Such apoint source is game changing in applications such as spotlighting orrange finding where parabolic reflectors or lensing optics can becombined with the point source to create highly collimated white lightspots that can travel drastically higher distances than ever possiblebefore using LEDs or bulb technology.

In some embodiments of the present invention the gallium and nitrogencontaining light emitting device may not be a laser device, but insteadmay be configured as a superluminescent diode or superluminescent lightemitting diode (SLED) device. For the purposes of this invention, a SLEDdevice and laser diode device can be used interchangeably. A SLED issimilar to a laser diode as it is based on an electrically drivenjunction that when injected with current becomes optically active andgenerates amplified spontaneous emission (ASE) and gain over a widerange of wavelengths. When the optical output becomes dominated by ASEthere is a knee in the light output versus current (LI) characteristicwherein the unit of light output becomes drastically larger per unit ofinjected current. This knee in the LI curve resembles the threshold of alaser diode, but is much softer. The advantage of a SLED device is thatSLED it can combine the unique properties of high optical emission powerand extremely high spatial brightness of laser diodes that make themideal for highly efficient long throw illumination and high brightnessphosphor excitation applications with a broad spectral width of (>5 nm)that provides for an improved eye safety and image quality in somecases. The broad spectral width results in a low coherence lengthsimilar to an LED. The low coherence length provides for an improvedsafety such has improved eye safety. Moreover, the broad spectral widthcan drastically reduce optical distortions in display or illuminationapplications. As an example, the well-known distortion pattern referredto as “speckle” is the result of an intensity pattern produced by themutual interference of a set of wavefronts on a surface or in a viewingplane. The general equations typically used to quantify the degree ofspeckle are inversely proportional to the spectral width. In the presentspecification, both a laser diode (LD) device and a superluminescentlight emitting diode (SLED) device are sometime simply referred to“laser device”.

A gallium and nitrogen containing laser diode (LD) or super luminescentlight emitting diode (SLED) may include at least a gallium and nitrogencontaining device having an active region and a cavity member and arecharacterized by emitted spectra generated by the stimulated emission ofphotons. In some embodiments a laser device emitting red laser light,i.e. light with wavelength between about 600 nm to 750 nm, are provided.These red laser diodes may include at least a gallium phosphorus andarsenic containing device having an active region and a cavity memberand are characterized by emitted spectra generated by the stimulatedemission of photons. The ideal wavelength for a red device for displayapplications is ˜635 nm, for green ˜530 nm and for blue 440-470 nm.There may be tradeoffs between what colors are rendered with a displayusing different wavelength lasers and also how bright the display is asthe eye is more sensitive to some wavelengths than to others.

In some embodiments according to the present invention, multiple laserdiode sources are configured to be excite the same phosphor or phosphornetwork. Combining multiple laser sources can offer many potentialbenefits according to this invention. First, the excitation power can beincreased by beam combining to provide a more powerful excitation spitand hence produce a brighter light source. In some embodiments, separateindividual laser chips are configured within the laser-phosphor lightsource. By including multiple lasers emitting 1 W, 2 W, 3 W, 4 W, 5 W ormore power each, the excitation power can be increased and hence thesource brightness would be increased. For example, by including two 3 Wlasers exciting the same phosphor area, the excitation power can beincreased to 6 W for double the white light brightness. In an examplewhere about 200 lumens of white are generated per 1 watt of laserexcitation power, the white light output would be increased from 600lumens to 1200 lumens. Beyond scaling the power of each single laserdiode emitter, the total luminous flux of the white light source can beincreased by continuing to increasing the total number of laser diodes,which can range from 10s, to 100s, and even to 1000s of laser diodeemitters resulting in 10s to 100s of kW of laser diode excitation power.Scaling the number of laser diode emitters can be accomplished in manyways such as including multiple lasers in a co-package, spatial beamcombining through conventional refractive optics or polarizationcombining, and others. Moreover, laser diode bars or arrays, andmini-bars can be utilized where each laser chip includes many adjacentlaser diode emitters. For example, a bar could include from 2 to 100laser diode emitters spaced from about 10 microns to about 400 micronsapart. Similarly, the reliability of the source can be increased byusing multiple sources at lower drive conditions to achieve the sameexcitation power as a single source driven at more harsh conditions suchas higher current and voltage.

As used herein, the term GaN substrate is associated with GroupIII-nitride based materials including GaN, InGaN, AlGaN, or other GroupIII containing alloys or compositions that are used as startingmaterials. Such starting materials include polar GaN substrates (i.e.,substrate where the largest area surface is nominally an (h k 1) planewherein h=k=0, and 1 is non-zero), non-polar GaN substrates (i.e.,substrate material where the largest area surface is oriented at anangle ranging from about 80-100 degrees from the polar orientationdescribed above towards an (h k 1) plane wherein 1=0, and at least oneof h and k is non-zero) or semi-polar GaN substrates (i.e., substratematerial where the largest area surface is oriented at an angle rangingfrom about +0.1 to 80 degrees or 110-179.9 degrees from the polarorientation described above towards an (h k 1) plane wherein 1=0, and atleast one of h and k is non-zero). Of course, there can be othervariations, modifications, and alternatives.

The laser diode device can be fabricated on a conventional orientationof a gallium and nitrogen containing film or substrate (e.g., GaN) suchas the polar c-plane, on a nonpolar orientation such as the m-plane, oron a semipolar orientation such as the {30-31}, {20-21}, {30-32},{11-22}, {10-11}, {30-3-1}, {20-2-1}, {30-3-2}, or offcuts of any ofthese polar, nonpolar, and semipolar planes within +/−10 degrees towardsa c-plane, and/or +/−10 degrees towards an a-plane, and/or +/−10 degreestowards an m-plane. In some embodiments, a gallium and nitrogencontaining laser diode laser diode includes a gallium and nitrogencontaining substrate. The substrate member may have a surface region onthe polar {0001} plane (c-plane), nonpolar plane (m-plane, a-plane), andsemipolar plain ({11-22}, {10-1-1}, {20-21}, {30-31}) or other planes ofa gallium and nitrogen containing substrate. The laser device can beconfigured to emit a laser beam characterized by one or more wavelengthsfrom about 390 nm to about 540 nm. In some embodiments the laser diodeis comprised from a III-nitride material emitting in the ultravioletregion with a wavelength of about 270 nm to about 390 nm.

FIG. 3 is a simplified schematic diagram of a laser diode formed on agallium and nitrogen containing substrate with the cavity aligned in adirection ended with cleaved or etched mirrors according to someembodiments of the present invention. In an example, the substratesurface 101 is a polar c-plane and the laser stripe region 110 ischaracterized by a cavity orientation substantially in an m-direction10, which is substantially normal to an a-direction 20, but can beothers such as cavity alignment substantially in the a-direction. Thelaser strip region 110 has a first end 107 and a second end 109 and isformed on an m-direction on a {0001} gallium and nitrogen containingsubstrate having a pair of cleaved or etched mirror structures, whichface each other. In another example, the substrate surface 101 is asemipolar plane and the laser stripe region 110 is characterized by acavity orientation substantially in a projection of a c-direction 10,which is substantially normal to an a-direction 20, but can be otherssuch as cavity alignment substantially in the a-direction. The laserstrip region 110 has a first end 107 and a second end 109 and is formedon a semipolar substrate such as a {40-41}, {30-31}, {20-21}, {40-4-1},{30-3-1}, {20-2-1}, {20-21}, or an offcut of these planes within +1-5degrees from the c-plane and a-plane gallium and nitrogen containingsubstrate. Optionally, the gallium nitride substrate member is a bulkGaN substrate characterized by having a nonpolar or semipolarcrystalline surface region, but can be others. The bulk GaN substratemay have a surface dislocation density below 10⁵ cm⁻² or 10⁵ to 10⁷cm⁻². The nitride crystal or wafer may include Al_(x)In_(y)Ga_(1−x−y)N,where 0≤x, y, x+y≤1. In one specific embodiment, the nitride crystalincludes GaN. In a embodiment, the GaN substrate has threadingdislocations, at a concentration between about 10⁵ cm⁻² and about 10⁸cm⁻², in a direction that is substantially orthogonal or oblique withrespect to the surface.

The exemplary laser diode devices in FIG. 3 have a pair of cleaved oretched mirror structures 109 and 107, which face each other. The firstcleaved or etched facet 109 includes a reflective coating and the secondcleaved or etched facet 107 includes no coating, an antireflectivecoating, or exposes gallium and nitrogen containing material. The firstcleaved or etched facet 109 is substantially parallel with the secondcleaved or etched facet 107. The first and second cleaved facets 109 and107 are provided by a scribing and breaking process according to anembodiment or alternatively by etching techniques using etchingtechnologies such as reactive ion etching (RIE), inductively coupledplasma etching (ICP), or chemical assisted ion beam etching (CAME), orother method. The reflective coating is selected from silicon dioxide,hafnia, and titania, tantalum pentoxide, zirconia, aluminum oxide,aluminum nitride, and aluminum oxynitride including combinations, andthe like. Depending upon the design, the mirror surfaces can alsoinclude an anti-reflective coating.

In a specific embodiment, the method of facet formation includessubjecting the substrates to a laser for pattern formation. In apreferred embodiment, the pattern is configured for the formation of apair of facets for a ridge laser. In a preferred embodiment, the pair offacets faces each other and is in parallel alignment with each other. Ina preferred embodiment, the method uses a UV (355 nm) laser to scribethe laser bars. In a specific embodiment, the laser is configured on asystem, which allows for accurate scribe lines configured in a differentpatterns and profiles. In an embodiment, the laser scribing can beperformed on the back-side, front-side, or both depending upon theapplication. Of course, there can be other variations, modifications,and alternatives.

In a specific embodiment, the method uses backside laser scribing or thelike. With backside laser scribing, the method preferably forms acontinuous line laser scribe that is perpendicular to the laser bars onthe backside of the GaN substrate. In a specific embodiment, the laserscribe is generally about 15-20 μm deep or other suitable depth.Preferably, backside scribing can be advantageous. That is, the laserscribe process does not depend on the pitch of the laser bars or otherlike pattern. Accordingly, backside laser scribing can lead to a higherdensity of laser bars on each substrate according to a preferredembodiment. In a specific embodiment, backside laser scribing, however,may lead to residue from the tape on the facets. In a specificembodiment, backside laser scribe often requires that the substratesface down on the tape. With front-side laser scribing, the backside ofthe substrate is in contact with the tape. Of course, there can be othervariations, modifications, and alternatives.

It is well known that etch techniques such as chemical assisted ion beametching (CAIBE), inductively coupled plasma (ICP) etching, or reactiveion etching (RIE) can result in smooth and vertical etched sidewallregions, which could serve as facets in etched facet laser diodes. Inthe etched facet process a masking layer is deposited and patterned onthe surface of the wafer. The etch mask layer could be comprised ofdielectrics such as silicon dioxide (SiO₂), silicon nitride(Si_(x)N_(y)), a combination thereof or other dielectric materials.Further, the mask layer could be comprised of metal layers such as Ni orCr, but could be comprised of metal combination stacks or stackscomprising metal and dielectrics. In another approach, photoresist maskscan be used either alone or in combination with dielectrics and/ormetals. The etch mask layer is patterned using conventionalphotolithography and etch steps. The alignment lithography could beperformed with a contact aligner or stepper aligner. Suchlithographically defined mirrors provide a high level of control to thedesign engineer. After patterning of the photoresist mask on top of theetch mask is complete, the patterns in then transferred to the etch maskusing a wet etch or dry etch technique. Finally, the facet pattern isthen etched into the wafer using a dry etching technique selected fromCAIBE, ICP, RIE and/or other techniques. The etched facet surfaces mustbe highly vertical of between about 87 and about 93 degrees or betweenabout 89 and about 91 degrees from the surface plane of the wafer. Theetched facet surface region must be very smooth with root mean squareroughness values of less than about 50 nm, 20 nm, 5 nm, or 1 nm. Lastly,the etched must be substantially free from damage, which could act asnonradiative recombination centers and hence reduce the catastrophicoptical mirror damage (COMD) threshold. CAME is known to provide verysmooth and low damage sidewalls due to the chemical nature of the etch,while it can provide highly vertical etches due to the ability to tiltthe wafer stage to compensate for any inherent angle in etch.

The laser stripe region 110 is characterized by a length and width. Thelength ranges from about 50 μm to about 3000 μm, but is preferablybetween about 10 μm and about 400 μm, between about 400 μm and about 800μm, or about 800 μm and about 1600 μm, but could be others. The stripealso has a width ranging from about 0.5 μm to about 50 μm, but ispreferably between about 0.8 μm and about 2.5 μm for single lateral modeoperation or between about 2.5 and about 50 μm for multi-lateral modeoperation, but can be other dimensions. In a specific embodiment, thepresent device has a width ranging from about 0.5 μm to about 1.5 μm, awidth ranging from about 1.5 μm to about 3.0 μm, a width ranging fromabout 3.0 μm to about 50 μm, and others. In a specific embodiment, thewidth is substantially constant in dimension, although there may beslight variations. The width and length are often formed using a maskingand etching process, which are commonly used in the art.

The laser stripe region 110 is provided by an etching process selectedfrom dry etching or wet etching. The device also has an overlyingdielectric region, which exposes a p-type contact region. Overlying thecontact region is a contact material, which may be metal or a conductiveoxide or a combination thereof. The p-type electrical contact may bedeposited by thermal evaporation, electron beam evaporation,electroplating, sputtering, or another suitable technique. Overlying thepolished region of the substrate is a second contact material, which maybe metal or a conductive oxide or a combination thereof and whichincludes the n-type electrical contact. The n-type electrical contactmay be deposited by thermal evaporation, electron beam evaporation,electroplating, sputtering, or another suitable technique.

In a specific embodiment, the laser device may emit red light with acenter wavelength between 600 nm and 750 nm. Such a device may includelayers of varying compositions of Al_(x)In_(y)Ga_(1−x−y)As_(z)P_(1−z),where x+y≤1 and z≤1. The red laser device includes at least an n-typeand p-type cladding layer, an n-type SCH of higher refractive index thanthe n-type cladding, a p-type SCH of higher refractive index than thep-type cladding and an active region where light is emitted. In aspecific embodiment, the laser stripe is provided by an etching processselected from dry etching or wet etching. In a preferred embodiment, theetching process is dry, but can be others. The device also has anoverlying dielectric region, which exposes the contact region. In aspecific embodiment, the dielectric region is an oxide such as silicondioxide, but can be others. Of course, there can be other variations,modifications, and alternatives. The laser stripe region ischaracterized by a length and width. The length ranges from about 50 μmto about 3000 μm, but is preferably between 10 μm and 400 μm, betweenabout 400 μm and 800 μm, or about 800 μm and 1600 μm, but could beothers such as greater than 1600 μm. The stripe region also has a widthranging from about 0.5 μm to about 80 μm, but is preferably between 0.8μm and 2.5 μm for single lateral mode operation or between 2.5 μm and 60μm for multi-lateral mode operation, but can be other dimensions. Thelaser strip region has a first end and a second end having a pair ofcleaved or etched mirror structures, which face each other. The firstfacet includes a reflective coating and the second facet includes nocoating, an antireflective coating, or exposes gallium and nitrogencontaining material. The first facet is substantially parallel with thesecond cleaved or etched facet.

Given the high gallium and nitrogen containing substrate costs,difficulty in scaling up gallium and nitrogen containing substrate size,the inefficiencies inherent in the processing of small wafers, andpotential supply limitations it becomes extremely desirable to maximizeutilization of available gallium and nitrogen containing substrate andoverlying epitaxial material. In the fabrication of lateral cavity laserdiodes, it is typically the case that minimum die size is determined bydevice components such as the wire bonding pads or mechanical handlingconsiderations, rather than by laser cavity widths. Minimizing die sizeis critical to reducing manufacturing costs as smaller die sizes allow agreater number of devices to be fabricated on a single wafer in a singleprocessing run. The current invention is a method of maximizing thenumber of devices which can be fabricated from a given gallium andnitrogen containing substrate and overlying epitaxial material byspreading out the epitaxial material onto a carrier wafer via a dieexpansion process.

Similar to an edge emitting laser diode, a SLED is typically configuredas an edge-emitting device wherein the high brightness, highlydirectional optical emission exits a waveguide directed outward from theside of the semiconductor chip. SLEDs are designed to have high singlepass gain or amplification for the spontaneous emission generated alongthe waveguide. However, unlike laser diodes, they are designed toprovide insufficient feedback to in the cavity to achieve the lasingcondition where the gain equals the total losses in the waveguidecavity. In a typical example, at least one of the waveguide ends orfacets is designed to provide very low reflectivity back into thewaveguide. Several methods can be used to achieve reduced reflectivityon the waveguide end or facet. In one approach an optical coating isapplied to at least one of the facets, wherein the optical coating isdesigned for low reflectivity such as less than 1%, less than 0.1%, lessthan 0.001%, or less than 0.0001% reflectivity. In another approach forreduced reflectivity the waveguide ends are designed to be tilted orangled with respect to the direction of light propagation such that thelight that is reflected back into the chip does not constructivelyinterfere with the light in the cavity to provide feedback. The tiltangle must be carefully designed around a null in the reflectivityversus angle relationship for optimum performance. The tilted or angledfacet approach can be achieved in a number of ways including providingan etched facet that is designed with an optimized angle lateral anglewith respect to the direction of light propagation. The angle of thetilt is pre-determined by the lithographically defined etched facetpatter. Alternatively, the angled output could be achieved by curvingand/or angling the waveguide with respect to a cleaved facet that formson a pre-determined crystallographic plane in the semiconductor chip.Another approach to reduce the reflectivity is to provide a roughened orpatterned surface on the facet to reduce the feedback to the cavity. Theroughening could be achieved using chemical etching and/or a dryetching, or with an alternative technique. Of course there may be othermethods for reduced feedback to the cavity to form a SLED device. Inmany embodiments a number of techniques can be used in combination toreduce the facet reflectivity including using low reflectivity coatingsin combination with angled or tilted output facets with respect to thelight propagation.

In a specific embodiment on a nonpolar Ga-containing substrate, thedevice is characterized by a spontaneously emitted light is polarized insubstantially perpendicular to the c-direction. In a preferredembodiment, the spontaneously emitted light is characterized by apolarization ratio of greater than 0.1 to about 1 perpendicular to thec-direction. In a preferred embodiment, the spontaneously emitted lightcharacterized by a wavelength ranging from about 430 nanometers to about470 nm to yield a blue emission, or about 500 nanometers to about 540nanometers to yield a green emission, and others. For example, thespontaneously emitted light can be violet (e.g., 395 to 420 nanometers),blue (e.g., 420 to 470 nm); green (e.g., 500 to 540 nm), or others. In apreferred embodiment, the spontaneously emitted light is highlypolarized and is characterized by a polarization ratio of greater than0.4. In another specific embodiment on a semipolar {20-21} Ga-containingsubstrate, the device is also characterized by a spontaneously emittedlight is polarized in substantially parallel to the a-direction orperpendicular to the cavity direction, which is oriented in theprojection of the c-direction.

In a specific embodiment, the present invention provides an alternativedevice structure capable of emitting 501 nm and greater light in a ridgelaser embodiment. The device is provided with the following epitaxiallygrown elements:

-   -   an n-GaN or n-AlGaN cladding layer with a thickness from 100 nm        to 3000 nm with Si doping level of 5×10¹⁷ cm⁻³ to 3×10¹⁸ cm⁻³;    -   an n-side SCH layer comprised of InGaN with molar fraction of        indium of between 2% and 15% and thickness from 20 nm to 250 nm;    -   a single quantum well or a multiple quantum well active region        comprised of at least two 2.0 nm to 8.5 nm InGaN quantum wells        separated by 1.5 nm and greater, and optionally up to about 12        nm, GaN or InGaN barriers;    -   a p-side SCH layer comprised of InGaN with molar a fraction of        indium of between 1% and 10% and a thickness from 15 nm to 250        nm or an upper GaN-guide layer;    -   an electron blocking layer comprised of AlGaN with molar        fraction of aluminum of between 0% and 22% and thickness from 5        nm to 20 nm and doped with Mg;    -   a p-GaN or p-AlGaN cladding layer with a thickness from 400 nm        to 1500 nm with Mg doping level of 2×10¹⁷ cm⁻³ to 2×10¹⁹ cm-3;        and    -   a p++-GaN contact layer with a thickness from 20 nm to 40 nm        with Mg doping level of 1×10¹⁹ cm⁻³ to 1×10²¹ cm⁻³.

A gallium and nitrogen containing laser diode laser device may alsoinclude other structures, such as a surface ridge architecture, a buriedheterostructure architecture, and/or a plurality of metal electrodes forselectively exciting the active region. For example, the active regionmay include first and second gallium and nitrogen containing claddinglayers and an indium and gallium containing emitting layer positionedbetween the first and second cladding layers. A laser device may furtherinclude an n-type gallium and nitrogen containing material and an n-typecladding material overlying the n-type gallium and nitrogen containingmaterial. In a specific embodiment, the device also has an overlyingn-type gallium nitride layer, an active region, and an overlying p-typegallium nitride layer structured as a laser stripe region. Additionally,the device may also include an n-side separate confinementhetereostructure (SCH), p-side guiding layer or SCH, p-AlGaN EBL, amongother features. In a specific embodiment, the device also has a p++ typegallium nitride material to form a contact region. In a specificembodiment, the p++ type contact region has a suitable thickness and mayrange from about 10 nm 50 nm, or other thicknesses. In a specificembodiment, the doping level can be higher than the p-type claddingregion and/or bulk region. In a specific embodiment, the p++ type regionhas doping concentration ranging from about 10¹⁹ to 10²¹ Mg/am³, andothers. The p++ type region preferably causes tunneling between thesemiconductor region and overlying metal contact region. In a specificembodiment, each of these regions is formed using at least an epitaxialdeposition technique of metal organic chemical vapor deposition (MOCVD),molecular beam epitaxy (MBE), or other epitaxial growth techniquessuitable for GaN growth. In a specific embodiment, the epitaxial layeris a high-quality epitaxial layer overlying the n-type gallium nitridelayer. In some embodiments the high-quality layer is doped, for example,with Si or O to form n-type material, with a dopant concentrationbetween about 10¹⁶ cm⁻³ and 10²⁰ cm⁻³.

FIG. 4 is a cross-sectional view of a laser device 200 according to someembodiments of the present disclosure. As shown, the laser deviceincludes gallium nitride substrate 203, which has an underlying n-typemetal back contact region 201. For example, the substrate 203 may becharacterized by a semipolar or nonpolar orientation. The device alsohas an overlying n-type gallium nitride layer 205, an active region 207,and an overlying p-type gallium nitride layer structured as a laserstripe region 209. Each of these regions is formed using at least anepitaxial deposition technique of MOCVD, MBE, or other epitaxial growthtechniques suitable for GaN growth. The epitaxial layer is ahigh-quality epitaxial layer overlying the n-type gallium nitride layer.In some embodiments the high-quality layer is doped, for example, withSi or O to form n-type material, with a dopant concentration betweenabout 10¹⁶ cm⁻³ and 10²⁰ cm⁻³.

An n-type Al_(u)In_(v)Ga_(1-u-v)N layer, where 0≤u, v, u+v≤1, isdeposited on the substrate. The carrier concentration may lie in therange between about 10¹⁶ cm⁻³ and 10²⁰ cm⁻³. The deposition may beperformed using MOCVD or MBE.

For example, the bulk GaN substrate is placed on a susceptor in an MOCVDreactor. After closing, evacuating, and back-filling the reactor (orusing a load lock configuration) to atmospheric pressure, the susceptoris heated to a temperature between about 1000 and about 1200 degreesCelsius in the presence of a nitrogen-containing gas. The susceptor isheated to approximately 900 to 1200 degrees Celsius under flowingammonia. A flow of a gallium-containing metalorganic precursor, such astrimethylgallium (TMG) or triethylgallium (TEG) is initiated, in acarrier gas, at a total rate between approximately 1 and 50 standardcubic centimeters per minute (sccm). The carrier gas may includehydrogen, helium, nitrogen, or argon. The ratio of the flow rate of thegroup V precursor (ammonia) to that of the group III precursor(trimethylgallium, triethylgallium, trimethylindium, trimethylaluminum)during growth is between about 2000 and about 12000. A flow of disilanein a carrier gas, with a total flow rate of between about 0.1 sccm and10 sccm, is initiated.

In one embodiment, the laser stripe region is p-type gallium nitridelayer 209. The laser stripe is provided by a dry etching process, butwet etching can be used. The dry etching process is an inductivelycoupled process using chlorine bearing species or a reactive ion etchingprocess using similar chemistries. The chlorine bearing species arecommonly derived from chlorine gas or the like. The device also has anoverlying dielectric region, which exposes a contact region 213. Thedielectric region is an oxide such as silicon dioxide or siliconnitride, and a contact region is coupled to an overlying metal layer215. The overlying metal layer is preferably a multilayered structurecontaining gold and platinum (Pt/Au), palladium and gold (Pd/Au), ornickel gold (Ni/Au), or a combination thereof. In some embodiments,barrier layers and more complex metal stacks are included.

Active region 207 preferably includes one to ten quantum-well regions ora double heterostructure region for light emission. Following depositionof the n-type Al_(u)In_(v)Ga_(1-u-v)N layer to achieve a desiredthickness, an active layer is deposited. The quantum wells arepreferably InGaN with GaN, AlGaN, InAlGaN, or InGaN barrier layersseparating them. In other embodiments, the well layers and barrierlayers include Al_(w)In_(x)Ga_(1−w−x)N and Al_(y)In_(z)Ga_(1−y−z)N,respectively, where 0≤w, x, y, z, w+x, y+z≤1, where w<u, y and/or x>v, zso that the bandgap of the well layer(s) is less than that of thebarrier layer(s) and the n-type layer. The well layers and barrierlayers each have a thickness between about 1 nm and about 20 nm. Thecomposition and structure of the active layer are chosen to providelight emission at a preselected wavelength. The active layer may be leftundoped (or unintentionally doped) or may be doped n-type or p-type.

The active region can also include an electron blocking region, and aseparate confinement heterostructure. The electron-blocking layer mayinclude Al_(s)In_(t)Ga_(1−s−t)N, where 0≤s, t, s+t≤1, with a higherbandgap than the active layer, and may be doped p-type. In one specificembodiment, the electron blocking layer includes AlGaN. In anotherembodiment, the electron blocking layer includes an AlGaN/GaNsuper-lattice structure, comprising alternating layers of AlGaN and GaN,each with a thickness between about 0.2 nm and about 5 nm.

As noted, the p-type gallium nitride or aluminum gallium nitridestructure is deposited above the electron blocking layer and activelayer(s). The p-type layer may be doped with Mg, to a level betweenabout 10¹⁶ cm⁻³ and 10²² cm⁻³, with a thickness between about 5 nm andabout 1000 nm. The outermost 1-50 nm of the p-type layer may be dopedmore heavily than the rest of the layer, so as to enable an improvedelectrical contact. The device also has an overlying dielectric region,for example, silicon dioxide, which exposes the contact region 213.

The metal contact is made of suitable material such as silver, gold,aluminum, nickel, platinum, rhodium, palladium, chromium, or the like.The contact may be deposited by thermal evaporation, electron beamevaporation, electroplating, sputtering, or another suitable technique.In a preferred embodiment, the electrical contact serves as a p-typeelectrode for the optical device. In another embodiment, the electricalcontact serves as an n-type electrode for the optical device. The laserdevices illustrated in FIG. 3 and FIG. 4 and described above aretypically suitable for relative low-power applications.

In various embodiments, the present invention realizes high output powerfrom a diode laser is by widening a portions of the laser cavity memberfrom the single lateral mode regime of 1.0-3.0 μm to the multi-lateralmode range 5.0-20 μm. In some cases, laser diodes having cavities at awidth of 50 μm or greater are employed.

The laser stripe length, or cavity length ranges from 100 to 3000 μm andemploys growth and fabrication techniques such as those described inU.S. patent application Ser. No. 12/759,273, filed Apr. 13, 2010, whichis incorporated by reference herein. As an example, laser diodes arefabricated on nonpolar or semipolar gallium containing substrates, wherethe internal electric fields are substantially eliminated or mitigatedrelative to polar c-plane oriented devices. It is to be appreciated thatreduction in internal fields often enables more efficient radiativerecombination. Further, the heavy hole mass is expected to be lighter onnonpolar and semipolar substrates, such that better gain properties fromthe lasers can be achieved.

Optionally, FIG. 4 illustrates an example cross-sectional diagram of agallium and nitrogen based laser diode device. The epitaxial devicestructure is formed on top of the gallium and nitrogen containingsubstrate member 203. The substrate member may be n-type doped with Oand/or Si doping. The epitaxial structures will contain n-side layers205 such as an n-type buffer layer comprised of GaN, AlGaN, AlINGaN, orInGaN and n-type cladding layers comprised of GaN, AlGaN, or AlInGaN.The n-typed layers may have thickness in the range of 0.3 μm to about 3μm or to about 5 μm and may be doped with an n-type carriers such as Sior O to concentrations between 1×10¹⁶ cm⁻³ to 1×10¹⁹ cm⁻³. Overlying then-type layers is the active region and waveguide layers 207. This regioncould contain an n-side waveguide layer or separate confinementheterostructure (SCH) such as InGaN to help with optical guiding of themode. The InGaN layer be comprised of 1 to 15% molar fraction of InNwith a thickness ranging from about 30 nm to about 250 nm and may bedoped with an n-type species such as Si. Overlying the SCH layer is thelight emitting regions which could be comprised of a doubleheterostructure or a quantum well active region. A quantum well activeregion could be comprised of 1 to 10 quantum wells ranging in thicknessfrom 1 nm to 20 nm comprised of InGaN. Barrier layers comprised of GaN,InGaN, or AlGaN separate the quantum well light emitting layers. Thebarriers range in thickness from 1 nm to about 25 nm. Overlying thelight emitting layers are optionally an AlGaN or InAlGaN electronblocking layer with 5% to about 35% AlN and optionally doped with ap-type species such as Mg. Also optional is a p-side waveguide layer orSCH such as InGaN to help with optical guiding of the mode. The InGaNlayer be comprised of 1 to 15% molar fraction of InN with a thicknessranging from 30 nm to about 250 nm and may be doped with an p-typespecies such as Mg. Overlying the active region and optional electronblocking layer and p-side waveguide layers is a p-cladding region and ap++ contact layer. The p-type cladding region is comprised of GaN,AlGaN, AlINGaN, or a combination thereof. The thickness of the p-typecladding layers is in the range of 0.3 μm to about 2 μm and is dopedwith Mg to a concentration of between 1×10¹⁶ cm⁻³ to 1×10¹⁹ cm⁻³. Aridge 211 is formed in the p-cladding region for lateral confinement inthe waveguide using an etching process selected from a dry etching or awet etching process. A dielectric material 213 such as silicon dioxideor silicon nitride or deposited on the surface region of the device andan opening is created on top of the ridge to expose a portion of the p++GaN layer. A p-contact 215 is deposited on the top of the device tocontact the exposed p++ contact region. The p-type contact may becomprised of a metal stack containing a of Au, Pd, Pt, Ni, Ti, or Ag andmay be deposited with electron beam deposition, sputter deposition, orthermal evaporation. A n-contact 201 is formed to the bottom of thesubstrate member. The n-type contact may be comprised of a metal stackcontaining Au, Al, Pd, Pt, Ni, Ti, or Ag and may be deposited withelectron beam deposition, sputter deposition, or thermal evaporation.

In multiple embodiments according to the present invention, the devicelayers include a super-luminescent light emitting diode or SLED. In allapplicable embodiments a SLED device can be interchanged with orcombined with laser diode devices according to the methods andarchitectures described in this invention. A SLED is in many wayssimilar to an edge emitting laser diode; however, the emitting facet ofthe device is designed so as to have a very low reflectivity. A SLED issimilar to a laser diode as it is based on an electrically drivenjunction that when injected with current becomes optically active andgenerates amplified spontaneous emission (ASE) and gain over a widerange of wavelengths. When the optical output becomes dominated by ASEthere is a knee in the light output versus current (LI) characteristicwherein the unit of light output becomes drastically larger per unit ofinjected current. This knee in the LI curve resembles the threshold of alaser diode, but is much softer. A SLED would have a layer structureengineered to have a light emitting layer or layers clad above and belowwith material of lower optical index such that a laterally guidedoptical mode can be formed. The SLED would also be fabricated withfeatures providing lateral optical confinement. These lateralconfinement features may consist of an etched ridge, with air, vacuum,metal or dielectric material surrounding the ridge and providing a lowoptical-index cladding. The lateral confinement feature may also beprovided by shaping the electrical contacts such that injected currentis confined to a finite region in the device. In such a “gain guided”structure, dispersion in the optical index of the light emitting layerwith injected carrier density provides the optical-index contrast neededto provide lateral confinement of the optical mode.

It is also possible for the laser diode or SLED ridge, or in the case ofa gain-guided device the electrically injected region, would not be ofuniform width. The purpose of this would be to produce a waveguide orcavity of larger width at one or both ends. This has two main advantagesover a ridge or injected region of uniform width. Firstly, the waveguidecan be shaped such that the resulting cavity can only sustain a singlelateral mode while allowing the total area of the device to besignificantly larger than that achievable in a device having a waveguideof uniform width. This increases the achievable optical power achievablein a device with a single lateral mode. Secondly, this allows for thecross-sectional area of the optical mode at the facets to besignificantly larger than in a single-mode device having a waveguide ofuniform width. Such a configuration reduces the optical power density ofthe device at the facet, and thereby reduces the likelihood thatoperation at high powers will result in optical damage to the facets.Single lateral mode devices may have some advantages in spectroscopy orin visible light communication where the single later mode results in asignificant reduction in spectral width relative to a multi-lateral modedevice with a wide ridge of uniform width. This would allow for morelaser devices of smaller differences in center wavelength to be includedin the same VLC emitter as the spectra would overlap less and be easierto demultiplex with filtered detectors. Optionally, both multi-mode andsingle-mode lasers would have significantly narrower spectra relative toLEDs with spectra of the same peak wavelength.

In an embodiment, the LD or SLED device is characterized by a ridge withnon-uniform width. The ridge is comprised by a first section of uniformwidth and a second section of varying width. The first section has alength between 100 and 500 μm long, though it may be longer. The firstsection has a width of between 1 and 2.5 μm, with a width preferablybetween 1 and 1.5 μm. The second section of the ridge has a first endand a second end. The first end connects with the first section of theridge and has the same width as the first section of the ridge. Thesecond end of the second section of the ridge is wider than the firstsection of the ridge, with a width between 5 and 50 μm and morepreferably with a width between 15 and 35 μm. The second section of theridge waveguide varies in width between its first and second endsmoothly. In some embodiments the second derivative of the ridge widthversus length is zero such that the taper of the ridge is linear. Insome embodiments, the second derivative is chosen to be positive ornegative. In general, the rate of width increase is chosen such that theridge does not expand in width significantly faster than the opticalmode. In specific embodiments, the electrically injected area ispatterned such that only a part of the tapered portion of the waveguideis electrically injected.

In an embodiment, multiple laser dice emitting at different wavelengthsare transferred to the same carrier wafer in close proximity to oneanother; preferably within one millimeter of each other, more preferablywithin about 200 micrometers of each other and most preferably withinabout 50 μm of each other. The laser die wavelengths are chosen to beseparated in wavelength by at least twice the full width at half maximumof their spectra. For example, three dice, emitting at 440 nm, 450 nmand 460 nm, respectively, are transferred to a single carrier chip witha separation between die of less than 50 μm and die widths of less than50 μm such that the total lateral separation, center to center, of thelaser light emitted by the die is less than 200 μm. The closeness of thelaser die allows for their emission to be easily coupled into the sameoptical train or fiber optic waveguide or projected in the far fieldinto overlapping spots. In a sense, the lasers can be operatedeffectively as a single laser light source.

Such a configuration offers an advantage in that each individual laserlight source could be operated independently to convey information usingfor example frequency and phase modulation of an RF signal superimposedon DC offset. The time-averaged proportion of light from the differentsources could be adjusted by adjusting the DC offset of each signal. Ata receiver, the signals from the individual laser sources would bedemultiplexed by use of notch filters over individual photodetectorsthat filter out both the phosphor derived component of the white lightspectra as well as the pump light from all but one of the laser sources.Such a configuration would offer an advantage over an LED based visiblelight communication (VLC) source in that bandwidth would scale easilywith the number of laser emitters. Of course, a similar embodiment withsimilar advantages could be constructed from SLED emitters.

After the laser diode chip fabrication as described above, the laserdiode can be mounted to a submount. In some examples the submount iscomprised of AlN, SiC, BeO, diamond, or other materials such as metals,ceramics, or composites. The submount can be the common support memberwherein the phosphor member of the CPoS would also be attached.Alternatively, the submount can be an intermediate submount intended tobe mounted to the common support member wherein the phosphor material isattached. The submount member may be characterized by a width, length,and thickness. In an example wherein the submount is the common supportmember for the phosphor and the laser diode chip the submount would havea width and length ranging in dimension from about 0.5 mm to about 5 mmor to about 15 mm and a thickness ranging from about 150 μm to about 2mm. In the example wherein the submount is an intermediate submountbetween the laser diode chip and the common support member it could becharacterized by width and length ranging in dimension from about 0.5 mmto about 5 mm and the thickness may range from about 50 μm to about 500μm. The laser diode is attached to the submount using a bonding process,a soldering process, a gluing process, or a combination thereof. In oneembodiment the submount is electrically isolating and has metal bondpads deposited on top. The laser chip is mounted to at least one ofthose metal pads. The laser chip can be mounted in a p-side down or ap-side up configuration. After bonding the laser chip, wire bonds areformed from the chip to the submount such that the final chip onsubmount (CoS) is completed and ready for integration.

A schematic diagram illustrating a CoS based on a conventional laserdiode formed on gallium and nitrogen containing substrate technologyaccording to this present invention is shown in FIG. 5 . The CoS iscomprised of submount material 301 configured to act as an intermediatematerial between a laser diode chip 302 and a final mounting surface.The submount is configured with electrodes 303 and 305 that may beformed with deposited metal layers such as Au. In one example, Ti/Pt/Auis used for the electrodes. Wirebonds 304 are configured to couple theelectrical power from the electrodes 303 and 305 on the submount to thelaser diode chip to generate a laser beam output 306 from the laserdiode. The electrodes 303 and 305 are configured for an electricalconnection to an external power source such as a laser driver, a currentsource, or a voltage source. Wirebonds 304 can be formed on theelectrodes to couple electrical power to the laser diode device andactivate the laser.

In another embodiment, the gallium and nitrogen containing laser diodefabrication includes an epitaxial release step to lift off theepitaxially grown gallium and nitrogen layers and prepare them fortransferring to a carrier wafer which could include the submount afterlaser fabrication. The transfer step requires precise placement of theepitaxial layers on the carrier wafer to enable subsequent processing ofthe epitaxial layers into laser diode devices. The attachment process tothe carrier wafer could include a wafer bonding step with a bondinterface comprised of metal-metal, semiconductor-semiconductor,glass-glass, dielectric-dielectric, or a combination thereof.

In yet another preferred variation of this CPoS white light source, aprocess for lifting-off gallium and nitrogen containing epitaxialmaterial and transferring it to the common support member can be used toattach the gallium and nitrogen containing laser epitaxial material to asubmount member. In this embodiment, the gallium and nitrogen epitaxialmaterial is released from the gallium and nitrogen containing substrateit was epitaxially grown on. As an example, the epitaxial material canbe released using a photoelectrochemical (PEC) etching technique. It isthen transferred to a submount material using techniques such as waferbonding wherein a bond interface is formed. For example, the bondinterface can be comprised of a Au—Au bond. The submount materialpreferably has a high thermal conductivity such as SiC, wherein theepitaxial material is subsequently processed to form a laser diode witha cavity member, front and back facets, and electrical contacts forinjecting current. After laser fabrication is complete, a phosphormaterial is introduced onto the submount to form an integrated whitelight source. The phosphor material may have an intermediate materialpositioned between the submount and the phosphor. The intermediatematerial may be comprised of a thermally conductive material such ascopper. The phosphor material can be attached to the submount usingconventional die attaching techniques using solders such as AuSn solder,but can be other techniques such as SAC solders such as SAC305, leadcontaining solder, or indium, but can be others. In an alternativeembodiment sintered Ag pastes or films can be used for the attachprocess at the interface. Sintered Ag attach material can be dispensedor deposited using standard processing equipment and cycle temperatureswith the added benefit of higher thermal conductivity and improvedelectrical conductivity. For example, AuSn has a thermal conductivity ofabout 50 W/m-K and electrical conductivity of about 16μΩcm whereaspressureless sintered Ag can have a thermal conductivity of about 125W/m-K and electrical conductivity of about 4μΩcm, or pressured sinteredAg can have a thermal conductivity of about 250 W/m-K and electricalconductivity of about 2.5 μΩcm. Due to the extreme change in melttemperature from paste to sintered form, (260° C.-900° C.), processescan avoid thermal load restrictions on downstream processes, allowingcompleted devices to have very good and consistent bonds throughout.Optimizing the bond for the lowest thermal impedance is a key parameterfor heat dissipation from the phosphor, which is critical to preventphosphor degradation and thermal quenching of the phosphor material. Thebenefits of using this embodiment with lifted-off and transferredgallium and nitrogen containing material are the reduced cost, improvedlaser performance, and higher degree of flexibility for integrationusing this technology.

In this embodiment, gallium and nitrogen containing epitaxial layers aregrown on a bulk gallium and nitrogen containing substrate. The epitaxiallayer stack includes at least a sacrificial release layer and the laserdiode device layers overlying the release layers. Following the growthof the epitaxial layers on the bulk gallium and nitrogen containingsubstrate, the semiconductor device layers are separated from thesubstrate by a selective wet etching process such as a PEC etchconfigured to selectively remove the sacrificial layers and enablerelease of the device layers to a carrier wafer. In one embodiment, abonding material is deposited on the surface overlying the semiconductordevice layers. A bonding material is also deposited either as a blanketcoating or patterned on the carrier wafer. Standard lithographicprocesses are used to selectively mask the semiconductor device layers.The wafer is then subjected to an etch process such as dry etch or wetetch processes to define via structures that expose the sacrificiallayers on the sidewall of the mesa structure. As used herein, the termmesa region or mesa is used to describe the patterned epitaxial materialon the gallium and nitrogen containing substrate and prepared fortransferring to the carrier wafer. The mesa region can be any shape orform including a rectangular shape, a square shape, a triangular shape,a circular shape, an elliptical shape, a polyhedron shape, or othershape. The term mesa shall not limit the scope of the present invention.

Following the definition of the mesa, a selective etch process isperformed to fully or partially remove the sacrificial layers whileleaving the semiconductor device layers intact. The resulting structureincludes undercut mesas comprised of epitaxial device layers. Theundercut mesas correspond to dice from which semiconductor devices willbe formed on. In some embodiments a protective passivation layer can beemployed on the sidewall of the mesa regions to prevent the devicelayers from being exposed to the selective etch when the etchselectivity is not perfect. In other embodiments a protectivepassivation is not needed because the device layers are not sensitive tothe selective etch or measures are taken to prevent etching of sensitivelayers such as shorting the anode and cathode. The undercut mesascorresponding to device dice are then transferred to the carrier waferusing a bonding technique wherein the bonding material overlying thesemiconductor device layers is joined with the bonding material on thecarrier wafer. The resulting structure is a carrier wafer comprisinggallium and nitrogen containing epitaxial device layers overlying thebonding region.

In a preferred embodiment PEC etching is deployed as the selective etchto remove the a sacrificial layers. PEC is a photo-assisted wet etchtechnique that can be used to etch GaN and its alloys. The processinvolves an above-band-gap excitation source and an electrochemical cellformed by the semiconductor and the electrolyte solution. In this case,the exposed (Al,In,Ga)N material surface acts as the anode, while ametal pad deposited on the semiconductor acts as the cathode. Theabove-band-gap light source generates electron-hole pairs in thesemiconductor. Electrons are extracted from the semiconductor via thecathode while holes diffuse to the surface of material to form an oxide.Since the diffusion of holes to the surface requires the band bending atthe surface to favor a collection of holes, PEC etching typically worksonly for n-type material although some methods have been developed foretching p-type material. The oxide is then dissolved by the electrolyteresulting in wet etching of the semiconductor. Different types ofelectrolyte including HCl, KOH, and HNO₃ have been shown to be effectivein PEC etching of GaN and its alloys. The etch selectivity and etch ratecan be optimized by selecting a favorable electrolyte. It is alsopossible to generate an external bias between the semiconductor and thecathode to assist with the PEC etching process.

In one embodiment thermocompression bonding is used to transfer thegallium and nitrogen epitaxial semiconductor layers to the carrierwafer. In this embodiment thermocompression bonding involves bonding ofthe epitaxial semiconductor layers to the carrier wafer at elevatedtemperatures and pressures using a bonding media 408 disposed betweenthe epitaxial layers and handle wafer. The bonding media 408 may becomprised of a number of different layers, but typically contain atleast one layer (the bonding layer 408) that is composed of a relativelyductile material with a high surface diffusion rate. In many cases thismaterial is comprised of Au, Al or Cu. The bonding media 408 may alsoinclude layers disposed between the bonding layer and the epitaxialmaterials or handle wafer that promote adhesion. For example, an Aubonding layer on a Si wafer may result in diffusion of Si to the bondinginterface, which would reduce the bonding strength. Inclusion of adiffusion barrier such as silicon oxide or nitride would limit thiseffect. Relatively thin layers of a second material may be applied onthe top surface of the bonding layer in order to promote adhesionbetween the bonding layers disposed on the epitaxial material andhandle. Some bonding layer materials of lower ductility than gold (e.g.Al, Cu etc.) or which are deposited in a way that results in a roughfilm (for example electrolytic deposition) may require planarization orreduction in roughness via chemical or mechanical polishing beforebonding, and reactive metals may require special cleaning steps toremove oxides or organic materials that may interfere with bonding.

Gold-gold metallic bonding is used as an example in this work, althougha wide variety of oxide bonds, polymer bonds, wax bonds, etc., arepotentially suitable. Submicron alignment tolerances are possible usingcommercially available die bonding equipment. In another embodiment ofthe invention the bonding layers can be a variety of bonding pairsincluding metal-metal, oxide-oxide, soldering alloys, photoresists,polymers, wax, etc. Only epitaxial die which are in contact with a bondbad on the carrier wafer will bond. Sub-micron alignment tolerances arepossible on commercially available die or flip chip bonders.

The carrier wafer can be chosen based on any number of criteriaincluding but not limited to cost, thermal conductivity, thermalexpansion coefficients, size, electrical conductivity, opticalproperties, and processing compatibility. The patterned epitaxy wafer,or donor, is prepared in such a way as to allow subsequent selectiverelease of bonded epitaxy regions, here-in referred to as die. Thepatterned carrier wafer is prepared such that bond pads are arranged inorder to enable the selective area bonding process. The bonding materialcan be a variety of media including but not limited to metals, polymers,waxes, and oxides. These wafers can be prepared by a variety of processflows, some embodiments of which are described below. In the firstselective area bond step, the epitaxy wafer is aligned with thepre-patterned bonding pads on the carrier wafer and a combination ofpressure, heat, and/or sonication is used to bond the mesas to thebonding pads.

In some embodiments of the invention the carrier wafer is anothersemiconductor material, a metallic material, or a ceramic material. Somepotential candidates include silicon, gallium arsenide, sapphire,silicon carbide, diamond, gallium nitride, AlN, polycrystalline AlN,indium phosphide, germanium, quartz, copper, copper tungsten, gold,silver, aluminum, stainless steel, or steel.

In some embodiments, the carrier wafer is selected based on size andcost. For example, ingle crystal silicon wafers are available indiameters up to 300 mm or 12 inch, and are most cost effective. Bytransferring gallium and nitrogen epitaxial materials from 2″ galliumand nitrogen containing bulk substrates to large silicon substrates of150 mm, 200 mm, or 300 mm diameter the effective area of thesemiconductor device wafer can be increases by factors of up to 36 orgreater. This feature of this invention allows for high quality galliumand nitrogen containing semiconductor devices to be fabricated in massvolume leveraging the established infrastructure in silicon foundries.

In some embodiments of the invention, the carrier wafer material ischosen such that it has similar thermal expansion properties togroup-III nitrides, high thermal conductivity, and is available as largearea wafers compatible with standard semiconductor device fabricationprocesses. The carrier wafer is then processed with structures enablingit to also act as the submount for the semiconductor devices.Singulation of the carrier wafers into individual die can beaccomplished either by sawing, cleaving, or a scribing and breakingprocess. By combining the functions of the carrier wafer and finishedsemiconductor device submount the number of components and operationsneeded to build a packaged device is reduced, thereby lowering the costof the final semiconductor device significantly.

In one embodiment of this invention, the bonding of the semiconductordevice epitaxial material to the carrier wafer process can be performedprior to the selective etching of the sacrificial region and subsequentrelease of the gallium and nitrogen containing substrate. FIG. 6 is aschematic illustration of a process comprised of first forming the bondbetween the gallium and nitrogen containing epitaxial material formed onthe gallium and nitrogen containing substrate and then subjecting asacrificial release material to the PEC etch process to release thegallium and nitrogen containing substrate. In this embodiment, anepitaxial material is deposited on the gallium and nitrogen containingsubstrate, such as a GaN substrate, through an epitaxial depositionprocess such as metal organic chemical vapor deposition (MOCVD),molecular beam epitaxy (MBE), or other. The epitaxial material includesat least a sacrificial release layer and a device layer. In someembodiments a buffer layer is grown on between the substrate surfaceregion and the sacrificial release region. Referring to FIG. 6 ,substrate wafer 500 is overlaid by a buffer layer 502, a selectivelyetchable sacrificial layer 504 and a collection of device layers 501.The bond layer 505 is deposited along with a cathode metal 506 that willbe used to facilitate the photoelectrochemical etch process forselectively removing the sacrificial layer 504.

In a preferred embodiment of this invention, the bonding process isperformed after the selective etching of the sacrificial region. Thisembodiment offers several advantages. One advantage is easier access forthe selective etchant to uniformly etch the sacrificial region acrossthe semiconductor wafer comprising a bulk gallium and nitrogencontaining substrate such as GaN and bulk gallium and nitrogencontaining epitaxial device layers. A second advantage is the ability toperform multiple bond steps. In one example, the “etch-then-bond”process flow can be deployed where the mesas are retained on thesubstrate by controlling the etch process such that not all parts of thesacrificial layer is removed. Referring to FIG. 6 , a substrate wafer500 is overlaid by a buffer layer 502, a selectively etchablesacrificial layer 504 and a collection of device layers 501. A bondlayer 505 is deposited along with a cathode metal 506 that will be usedto facilitate the photoelectrochemical etch process for selectivelyremoving the sacrificial layer 504. The selective etch process iscarried out to the point where only a small fraction of the sacrificiallayer 504 is remaining, such that multiple mesas or mesa regions areformed and retained on the substrate, but the unetched portions of thesacrificial layer 504 are easily broken during or after the mesas arebonded to a carrier wafer 508.

A critical challenge of the etch-then-bond embodiment is mechanicallysupporting the undercut epitaxial device layer mesa region fromspatially shifting prior to the bonding step. If the mesas shift theability to accurately align and arrange them to the carrier wafer willbe compromised, and hence the ability to manufacture with acceptableyields. This challenge mechanically fixing the mesa regions in placeprior to bonding can be achieved in several ways. In a preferredembodiment, anchor regions 503 are used to mechanically support themesas to the gallium and nitrogen containing substrate prior to thebonding step wherein they are releases from the gallium and nitrogencontaining substrate 500 and transferred to the carrier wafer 508.

Other than typical GaN based laser devices, undercut AlInGaAsP basedlaser devices can be produced in a manner similar to GaN based laserdiodes described in this invention. There are a number of wet etchesthat etch some AlInGaAsP alloys selectively. In one embodiment, anAlGaAs or AlGaP sacrificial layer could be grown clad with GaAs etchstop layers. When the composition of Al_(x)Ga_(1-z)As andAl_(x)Ga_(1-x)P is high (x>0.5) AlGaAs can be etched with almostcomplete selectivity (i.e. etch rate of AlGaAs>10⁶ times that of GaAs)when etched with HF. InGaP and AlInP with high InP and AlP compositionscan be etched with HCl selectively relative to GaAs. GaAs can be etchedselectively relative to AlGaAs using C₆H₈O₇:H₂O₂:H₂O. There are a numberof other combinations of sacrificial layer, etch-stop layer and etchchemistry which are widely known to those knowledgeable in the art ofmicromachining AlInGaAsP alloys.

In an embodiment, the AlInGaAsP device layers are exposed to the etchsolution which is chosen along with the sacrificial layer compositionsuch that only the sacrificial layers experience significant etching.The active region can be prevented from etching during thecompositionally selective etch using an etch resistant protective layer,such as like silicon dioxide, silicon nitride, metals or photoresistamong others, on the sidewall. This step is followed by the depositionof a protective insulating layer on the mesa sidewalls, which serves toblock etching of the active region during the later sacrificial regionundercut etching step. A second top down etch is then performed toexpose the sacrificial layers and bonding metal is deposited. With thesacrificial region exposed a compositionally selective etch is used toundercut the mesas. At this point, the selective area bonding process isused to continue fabricating devices. The device layers should beseparated from the sacrificial layers by a layer of material that isresistant to etching. This is to prevent etching into the device layersafter partially removing the sacrificial layers.

In a preferred embodiment, the semiconductor device epitaxy materialwith the underlying sacrificial region is fabricated into a dense arrayof mesas on the gallium and nitrogen containing bulk substrate with theoverlying semiconductor device layers. The mesas are formed using apatterning and a wet or dry etching process wherein the patterningincludes a lithography step to define the size and pitch of the mesaregions. Dry etching techniques such as reactive ion etching,inductively coupled plasma etching, or chemical assisted ion beametching are candidate methods. Alternatively, a wet etch can be used.The etch is configured to terminate at or below a sacrificial regionbelow the device layers. This is followed by a selective etch processsuch as PEC to fully or partially etch the exposed sacrificial regionsuch that the mesas are undercut. This undercut mesa pattern pitch willbe referred to as the ‘first pitch’. The first pitch is often a designwidth that is suitable for fabricating each of the epitaxial regions onthe substrate, while not large enough for the desired completedsemiconductor device design, which often desire larger non-activeregions or regions for contacts and the like. For example, these mesaswould have a first pitch ranging from about 5 μm to about 500 μm or toabout 5000 μm. Each of these mesas is a ‘die’.

In a preferred embodiment, these dice are transferred to a carrier waferat a second pitch using a selective bonding process such that the secondpitch on the carrier wafer is greater than the first pitch on thegallium and nitrogen containing substrate. In this embodiment the diceare on an expanded pitch for so called “die expansion”. In an example,the second pitch is configured with the dice to allow each die with aportion of the carrier wafer to be a semiconductor device, includingcontacts and other components. For example, the second pitch would beabout 50 μm to about 1000 μm or to about 5000 μm, but could be as largeat about 3-10 mm or greater in the case where a large semiconductordevice chip is required for the application. The larger second pitchcould enable easier mechanical handling without the expense of thecostly gallium and nitrogen containing substrate and epitaxial material,allow the real estate for additional features to be added to thesemiconductor device chip such as bond pads that do not require thecostly gallium and nitrogen containing substrate and epitaxial material,and/or allow a smaller gallium and nitrogen containing epitaxial wafercontaining epitaxial layers to populate a much larger carrier wafer forsubsequent processing for reduced processing cost. For example, a 4 to 1die expansion ratio would reduce the density of the gallium and nitrogencontaining material by a factor of 4, and hence populate an area on thecarrier wafer 4 times larger than the gallium and nitrogen containingsubstrate. This would be equivalent to turning a 2″ gallium and nitrogensubstrate into a 4″ carrier wafer. In particular, the present inventionincreases utilization of substrate wafers and epitaxy material through aselective area bonding process to transfer individual die of epitaxymaterial to a carrier wafer in such a way that the die pitch isincreased on the carrier wafer relative to the original epitaxy wafer.The arrangement of epitaxy material allows device components which donot require the presence of the expensive gallium and nitrogencontaining substrate and overlying epitaxy material often fabricated ona gallium and nitrogen containing substrate to be fabricated on thelower cost carrier wafer, allowing for more efficient utilization of thegallium and nitrogen containing substrate and overlying epitaxymaterial.

FIG. 7 is a schematic representation of the die expansion process withselective area bonding according to the present invention. A devicewafer is prepared for bonding in accordance with an embodiment of thisinvention. The device wafer consists of a substrate 606, buffer layers603, a fully removed sacrificial layer 609, device layers 602, bondingmedia 601, cathode metal 605, and an anchor material 604. Thesacrificial layer 609 is removed in the PEC etch with the anchormaterial 604 is retained. The mesa regions formed in the gallium andnitrogen containing epitaxial wafer form dice of epitaxial material andrelease layers defined through processing. Individual epitaxial materialdie are formed at first pitch. A carrier wafer is prepared consisting ofthe carrier wafer substrate 607 and bond pads 608 at second pitch. Thesubstrate 606 is aligned to the carrier wafer 607 such that a subset ofthe mesa on the gallium and nitrogen containing substrate 606 with afirst pitch aligns with a subset of bond pads 608 on the carrier wafer607 at a second pitch. Since the first pitch is greater than the secondpitch and the mesas will include device die, the basis for die expansionis established. The bonding process is carried out and upon separationof the substrate from the carrier wafer 607 the subset of mesas on thesubstrate 606 are selectively transferred to the carrier wafer 607. Theprocess is then repeated with a second set of mesas and bond pads 608 onthe carrier wafer 607 until the carrier wafer 607 is populated fully byepitaxial mesas. The gallium and nitrogen containing epitaxy substrate201 can now optionally be prepared for reuse.

In the example depicted in FIG. 7 , one quarter of the epitaxial dice onthe epitaxy wafer 606 are transferred in this first selective bond step,leaving three quarters on the epitaxy wafer 606. The selective areabonding step is then repeated to transfer the second quarter, thirdquarter, and fourth quarter of the epitaxial die to the patternedcarrier wafer 607. This selective area bond may be repeated any numberof times and is not limited to the four steps depicted in FIG. 7 . Theresult is an array of epitaxial die on the carrier wafer 607 with awider die pitch than the original die pitch on the epitaxy wafer 606.The die pitch on the epitaxial wafer 606 will be referred to as pitch 1,and the die pitch on the carrier wafer 607 will be referred to as pitch2, where pitch 2 is greater than pitch 1.

In one embodiment the bonding between the carrier wafer and the galliumand nitrogen containing substrate with epitaxial layers is performedbetween bonding layers that have been applied to the carrier and thegallium and nitrogen containing substrate with epitaxial layers. Thebonding layers can be a variety of bonding pairs including metal-metal,oxide-oxide, soldering alloys, photoresists, polymers, wax, etc. Onlyepitaxial dice which are in contact with a bond bad 608 on the carrierwafer 607 will bond. Sub-micron alignment tolerances are possible oncommercial die bonders. The epitaxy wafer 606 is then pulled away,breaking the epitaxy material at a weakened epitaxial release layer 609such that the desired epitaxial layers remain on the carrier wafer 607.Herein, a ‘selective area bonding step’ is defined as a single iterationof this process.

In one embodiment, the carrier wafer 607 is patterned in such a way thatonly selected mesas come in contact with the metallic bond pads 608 onthe carrier wafer 607. When the epitaxy substrate 606 is pulled away thebonded mesas break off at the weakened sacrificial region, while theun-bonded mesas remain attached to the epitaxy substrate 606. Thisselective area bonding process can then be repeated to transfer theremaining mesas in the desired configuration. This process can berepeated through any number of iterations and is not limited to the twoiterations depicted in FIG. 7 . The carrier wafer can be of any size,including but not limited to about 2 inch, 3 inch, 4 inch, 6 inch, 8inch, and 12 inch. After all desired mesas have been transferred, asecond bandgap selective PEC etching can be optionally used to removeany remaining sacrificial region material to yield smooth surfaces. Atthis point standard semiconductor device processes can be carried out onthe carrier wafer. Another embodiment of the invention incorporates thefabrication of device components on the dense epitaxy wafers before theselective area bonding steps.

In an example, the present invention provides a method for increasingthe number of gallium and nitrogen containing semiconductor deviceswhich can be fabricated from a given epitaxial surface area; where thegallium and nitrogen containing epitaxial layers overlay gallium andnitrogen containing substrates. The gallium and nitrogen containingepitaxial material is patterned into die with a first die pitch; the diefrom the gallium and nitrogen containing epitaxial material with a firstpitch is transferred to a carrier wafer to form a second die pitch onthe carrier wafer; the second die pitch is larger than the first diepitch.

Once the laser diode epitaxial structure has been transferred to thecarrier wafer as described in this invention, wafer level processing canbe used to fabricate the dice into laser diode devices. The waferprocess steps may be similar to those described in this specificationfor more conventional laser diodes. For example, in many embodiments thebonding media and dice will have a total thickness of less than about 7μm, making it possible to use standard photoresist, photoresistdispensing technology and contact and projection lithography tools andtechniques to pattern the wafers. The aspect ratios of the features arecompatible with deposition of thin films, such as metal and dielectriclayers, using evaporators, sputter and CVD deposition tools.

The laser diode device may have laser stripe region formed in thetransferred gallium and nitrogen containing epitaxial layers. In thecase where the laser is formed on a polar c-plane, the laser diodecavity can be aligned in the m-direction with cleaved or etched mirrors.Alternatively, in the case where the laser is formed on a semipolarplane, the laser diode cavity can be aligned in a projection of ac-direction. The laser strip region has a first end and a second end andis formed on a gallium and nitrogen containing substrate having a pairof cleaved mirror structures, which face each other. The first cleavedfacet includes a reflective coating and the second cleaved facetincludes no coating, an antireflective coating, or exposes gallium andnitrogen containing material. The first cleaved facet is substantiallyparallel with the second cleaved facet. The first and second cleavedfacets are provided by a scribing and breaking process according to anembodiment or alternatively by etching techniques using etchingtechnologies such as reactive ion etching (RIE), inductively coupledplasma etching (ICP), or chemical assisted ion beam etching (CAME), orother method. Typical gases used in the etching process may include Cland/or BCl₃. The first and second mirror surfaces each include areflective coating. The coating is selected from silicon dioxide,hafnia, and titania, tantalum pentoxide, zirconia, includingcombinations, and the like. Depending upon the design, the mirrorsurfaces can also include an anti-reflective coating.

In a specific embodiment, the method of facet formation includessubjecting the substrates to a laser for pattern formation. In apreferred embodiment, the pattern is configured for the formation of apair of facets for a ridge lasers. In a preferred embodiment, the pairof facets faces each other and is in parallel alignment with each other.In a preferred embodiment, the method uses a UV (355 nm) laser to scribethe laser bars. In a specific embodiment, the laser is configured on asystem, which allows for accurate scribe lines configured in a differentpatterns and profiles. In some embodiments, the laser scribing can beperformed on the back-side, front-side, or both depending upon theapplication. Of course, there can be other variations, modifications,and alternatives.

It is well known that etch techniques such as chemical assisted ion beametching (CAIBE), inductively coupled plasma (ICP) etching, or reactiveion etching (RIE) can result in smooth and vertical etched sidewallregions, which could serve as facets in etched facet laser diodes. Inthe etched facet process a masking layer is deposited and patterned onthe surface of the wafer. The etch mask layer could be comprised ofdielectrics such as silicon dioxide (SiO₂), silicon nitride(Si_(x)N_(y)), a combination thereof or other dielectric materials.Further, the mask layer could be comprised of metal layers such as Ni orCr, but could be comprised of metal combination stacks or stackscomprising metal and dielectrics. In another approach, photoresist maskscan be used either alone or in combination with dielectrics and/ormetals. The etch mask layer is patterned using conventionalphotolithography and etch steps. The alignment lithography could beperformed with a contact aligner or stepper aligner. Suchlithographically defined mirrors provide a high level of control to thedesign engineer. After patterning of the photoresist mask on top of theetch mask is complete, the patterns in then transferred to the etch maskusing a wet etch or dry etch technique. Finally, the facet pattern isthen etched into the wafer using a dry etching technique selected fromCAIBE, ICP, RIE and/or other techniques. The etched facet surfaces mustbe highly vertical of between about 87 and about 93 degrees or betweenabout 89 and about 91 degrees from the surface plane of the wafer. Theetched facet surface region must be very smooth with root mean squareroughness values of less than about 50 nm, 20 nm, 5 nm, or 1 nm. Lastly,the etched must be substantially free from damage, which could act asnon-radiative recombination centers and hence reduce the COMD threshold.CAME is known to provide very smooth and low damage sidewalls due to thechemical nature of the etch, while it can provide highly vertical etchesdue to the ability to tilt the wafer stage to compensate for anyinherent angle in etch.

In a specific embodiment, the plurality of donor epitaxial wafers may becomprised of device layers emitting at substantially differentwavelengths. For example, a blue device emitting at around 450 nm may bebonded adjacent to both a green device emitting at around 530 nm and ared device made from AlInGaAsP layers emitting at around 630 nm. Such aconfiguration would result in a controllable light source emittingcombinations or red, green and blue light that could be used forillumination or the generation of images.

In alternative embodiments, structures comprised of gallium and arsenicmaterials emitting in the 700 nm to 1100 nm range or structurescomprised of indium and phosphorous materials emitting in the 1100 nm to2000 nm range are transferred to the same carrier as the gallium andnitrogen containing structures emitting in the visible wavelength range.Such a configuration resulting in a controllable light source emittingin both the visible and IR wavelength ranges would be well suited forthe present dual band emitting illumination source invention disclosedhere.

In an embodiment, the device layers include a super-luminescent lightemitting diode or SLED. A SLED is in many ways similar to an edgeemitting laser diode; however, the emitting facet of the device isdesigned so as to have a very low reflectivity. A SLED is similar to alaser diode as it is based on an electrically driven junction that wheninjected with current becomes optically active and generates amplifiedspontaneous emission (ASE) and gain over a wide range of wavelengths.When the optical output becomes dominated by ASE there is a knee in thelight output versus current (LI) characteristic wherein the unit oflight output becomes drastically larger per unit of injected current.This knee in the LI curve resembles the threshold of a laser diode, butis much softer. A SLED would have a layer structure engineered to have alight emitting layer or layers clad above and below with material oflower optical index such that a laterally guided optical mode can beformed. The SLED would also be fabricated with features providinglateral optical confinement. These lateral confinement features mayconsist of an etched ridge, with air, vacuum, metal or dielectricmaterial surrounding the ridge and providing a low optical-indexcladding. The lateral confinement feature may also be provided byshaping the electrical contacts such that injected current is confinedto a finite region in the device. In such a “gain guided” structure,dispersion in the optical index of the light emitting layer withinjected carrier density provides the optical-index contrast needed toprovide lateral confinement of the optical mode. The emission spectralwidth is typically substantially wider (>5 nm) than that of a laserdiode and offer advantages with respect to reduced image distortion indisplays, increased eye safety, and enhanced capability in measurementand spectroscopy applications.

The laser stripe is characterized by a length and width. The lengthranges from about 50 μm to about 3000 μm, but is preferably betweenabout 10 μm and about 400 μm, between about 400 μm and about 800 μm, orabout 800 μm and about 1600 μm, but could be others such as greater than1600 μm. The stripe also has a width ranging from about 0.5 μm to about50 μm, but is preferably between about 0.8 μm and about 2.5 μm forsingle lateral mode operation or between about 2.5 μm and about 80 μmfor multi-lateral mode operation, but can be other dimensions. In aspecific embodiment, the present device has a width ranging from about0.5 μm to about 1.5 μm, a width ranging from about 1.5 μm to about 3.0μm, a width ranging from about 3.0 μm to about 360 μm, and others. In aspecific embodiment, the width is substantially constant in dimension,although there may be slight variations. The width and length are oftenformed using a masking and etching process, which are commonly used inthe art.

The laser stripe is provided by an etching process selected from dryetching or wet etching. The device also has an overlying dielectricregion, which exposes a p-type contact region. Overlying the contactregion is a contact material, which may be metal or a conductive oxideor a combination thereof. The p-type electrical contact may be depositedby thermal evaporation, electron beam evaporation, electroplating,sputtering, or another suitable technique. Overlying the polished regionof the substrate is a second contact material, which may be metal or aconductive oxide or a combination thereof and which includes the n-typeelectrical contact. The n-type electrical contact may be deposited bythermal evaporation, electron beam evaporation, electroplating,sputtering, or another suitable technique.

An example of a processed laser diode cross-section according to oneembodiment of the present invention is shown in FIG. 8 . In this examplean n-contact 801 is formed on top of n-type gallium and nitrogen contactlayer 802 and n-type cladding layer 803 that have been etched to form aridge waveguide 804. The n-type cladding layer 803 overlies an n-sidewaveguide layer or separate confinement heterostructure (SCH) layer 805and the n-side SCH overlies an active region 806 that contains lightemitting layers such as quantum wells. The active region overlies anoptional p-side SCH layer 807 and an electron blocking layer (EBL) 808.The optional p-side SCH layer overlies the p-type cladding 809 and ap-contact layer 810. Underlying the p-contact layer 810 is a metal stack811 that contains the p-type contact and bond metal used to attach thetransferred gallium and nitrogen containing epitaxial layers to thecarrier wafer 812.

Once the laser diodes have been fully processed within the gallium andnitrogen containing layers that have been transferred to the carrierwafer, the carrier wafer must be diced. Several techniques can be usedto dice the carrier wafer and the optimal process will depend on thematerial selection for the carrier wafer. As an example, for Si, InP, orGaAs carrier wafers that cleave very easily, a cleaving process can beused wherein a scribing and breaking process using conventional diamondscribe techniques may be most suitable. For harder materials such asGaN, AlN, SiC, sapphire, or others where cleaving becomes more difficulta laser scribing and breaking technique may be most suitable. In otherembodiments a sawing process may be the most optimal way to dice thecarrier wafer into individual laser chips. In a sawing process a rapidlyrotating blade with hard cutting surfaces like diamond are used,typically in conjunction with spraying water to cool and lubricate theblade. Example saw tools used to commonly dice wafers include Disco sawsand Accretech saws.

A schematic diagram illustrating a CoS based on lifted off andtransferred epitaxial gallium and nitrogen containing layers accordingto this present invention is shown in FIG. 9 . The CoS is comprised ofsubmount material 901 configured from the carrier wafer with thetransferred epitaxial material with a laser diode configured within theepitaxy 902. Electrodes 903 and 904 are electrically coupled to then-side and the p-side of the laser diode device and configured totransmit power from an external source to the laser diode to generate alaser beam output 905 from the laser diode. The electrodes areconfigured for an electrical connection to an external power source suchas a laser driver, a current source, or a voltage source. Wirebonds canbe formed on the electrodes to couple the power to the laser diodedevice. This integrated CoS device with transferred epitaxial materialoffers advantages over the conventional configuration such as size,cost, and performance due to the low thermal impedance.

Further process and device description for this embodiment describinglaser diodes formed in gallium and nitrogen containing epitaxial layersthat have been transferred from the native gallium and nitrogencontaining substrates are described in U.S. patent application Ser. No.14/312,427 and U.S. Patent Publication No. 2015/0140710, which areincorporated by reference herein. As an example, this technology of GaNtransfer can enable lower cost, higher performance, and a more highlymanufacturable process flow.

The present invention combines gallium and nitrogen containing laserwith wavelength converter members emitting the in the visible spectrumto comprise a laser based white light source. In a preferred embodiment,the visible wavelength converter member is comprised of a phosphormember, wherein careful phosphor selection is a key consideration withinthe laser based white light source. The phosphor must be able towithstand the extreme optical intensity and associated heating inducedby the laser excitation spot without severe degradation. Importantcharacteristics to consider for phosphor selection include:

-   -   A high conversion efficiency of optical excitation power to        white light lumens. In the example of a blue laser diode        exciting a yellow phosphor, a conversion efficiency of over 150        lumens per optical watt, or over 200 lumens per optical watt, or        over 300 lumens per optical watt is desired.    -   A high optical damage threshold capable of withstanding 1-20 W        of laser power in a spot comprising a diameter of 1 mm, 500 μm,        200 μm, 100 μm, or even 50 μm.    -   High thermal damage threshold capable of withstanding        temperatures of over 150° C., over 200° C., or over 300° C.        without decomposition.    -   A low thermal quenching characteristic such that the phosphor        remains efficient as it reaches temperatures of over 150° C.,        200° C., or 250° C.    -   A high thermal conductivity to dissipate the heat and regulate        the temperature. Thermal conductivities of greater than 3 W/m·K,        greater than 5 W/m-K, greater than 10 W/m·K, and even greater        than 15 W/m·K are desirable.    -   A proper phosphor emission color for the application.    -   A suitable porosity characteristic that leads to the desired        scattering of the coherent excitation without unacceptable        reduction in thermal conductivity or optical efficiency.    -   A proper form factor for the application. Such form factors        include, but are not limited to blocks, plates, disks, spheres,        cylinders, rods, or a similar geometrical element. Proper choice        will be dependent on whether phosphor is operated in        transmissive or reflective mode and on the absorption length of        the excitation light in the phosphor.    -   A surface condition optimized for the application. In an        example, the phosphor surfaces can be intentionally roughened        for improved light extraction.

In a preferred embodiment, the laser based white light source contains ablue laser diode operating in the 420 nm to 480 nm wavelength rangecombined with a phosphor material providing a yellowish emission in the530 nm to 600 nm range such that when mixed with the blue emission ofthe laser diode a white light is produced. For example, to meet a whitecolor point on the black body line the energy of the combined spectrummay be comprised of about 30% from the blue laser emission and about 70%from the yellow phosphor emission, or about 15% from the blue laseremission and about 85% from the yellow phosphor emission. In otherembodiments phosphors with red, green, yellow, and even blue emissioncan be used in combination with the laser diode excitation sources inthe violet, ultra-violet, or blue wavelength range to produce a whitelight with color mixing. Although such white light systems may be morecomplicated due to the use of more than one phosphor member, advantagessuch as improved color rendering could be achieved.

In an example, the light emitted from the laser diodes is partiallyconverted by the phosphor element. In an example, the partiallyconverted light emitted generated in the phosphor element results in acolor point, which is white in appearance. In an example, the colorpoint of the white light is located on the Planckian blackbody locus ofpoints. In an example, the color point of the white light is locatedwithin du′v′ of less than 0.010 of the Planckian blackbody locus ofpoints. In an example, the color point of the white light is preferablylocated within du′v′ of less than 0.03 of the Planckian blackbody locusof points.

The phosphor material can be operated in a transmissive mode, areflective mode, or a combination of a transmissive mode and reflectivemode, or other modes. The phosphor material is characterized by aconversion efficiency, a resistance to thermal damage, a resistance tooptical damage, a thermal quenching characteristic, a porosity toscatter excitation light, and a thermal conductivity. In a preferredembodiment the phosphor material is comprised of a yellow emitting YAGmaterial doped with Ce with a conversion efficiency of greater than 100lumens per optical watt, greater than 200 lumens per optical watt, orgreater than 300 lumens per optical watt, and can be a polycrystallineceramic material or a single crystal material.

In some embodiments of the present invention, the environment of thephosphor can be independently tailored to result in high efficiency withlittle or no added cost. Phosphor optimization for laser diodeexcitation can include high transparency, scattering or non-scatteringcharacteristics, and use of ceramic phosphor plates. Decreasedtemperature sensitivity can be determined by doping levels. A reflectorcan be added to the backside of a ceramic phosphor, reducing loss. Thephosphor can be shaped to increase in-coupling, increase out-coupling,and/or reduce back reflections. Surface roughening is a well-known meansto increase extraction of light from a solid material. Coatings,mirrors, or filters can be added to the phosphors to reduce the amountof light exiting the non-primary emission surfaces, to promote moreefficient light exit through the primary emission surface, and topromote more efficient in-coupling of the laser excitation light. Ofcourse, there can be additional variations, modifications, andalternatives.

In some embodiments, certain types of phosphors will be best suited inthis demanding application with a laser excitation source. As anexample, ceramic yttrium aluminum garnets (YAG) doped with Ce³⁺ ions, orYAG based phosphors can be ideal candidates. They are doped with speciessuch as Ce to achieve the proper emission color and are often comprisedof a porosity characteristic to scatter the excitation source light, andnicely break up the coherence in laser excitation. As a result of itscubic crystal structure the YAG:Ce can be prepared as a highlytransparent single crystal as well as a polycrystalline bulk material.The degree of transparency and the luminescence are depending on thestoichiometric composition, the content of dopant, and entire processingand sintering route. The transparency and degree of scattering centerscan be optimized for a homogenous mixture of blue and yellow light. TheYAG:Ce can be configured to emit a green emission. In some embodimentsthe YAG can be doped with Eu to emit a red emission. In some embodimentsthe phosphor peak emission wavelength is about 525 nm, about 540 nm,about 660 nm, or at a wavelength in between these peak wavelengths.

In a preferred embodiment according to this invention, the white lightsource is configured with a ceramic polycrystalline YAG:Ce phosphorscomprising an optical conversion efficiency of greater than 100 lumensper optical excitation watt, of greater than 200 lumens per opticalexcitation watt, or even greater than 300 lumens per optical excitationwatt. Additionally, the ceramic YAG:Ce phosphors is characterized by atemperature quenching characteristics above 150° C., above 200° C., orabove 250° C. and a high thermal conductivity of 5-10 W/m·K toeffectively dissipate heat to a heat sink member and keep the phosphorat an operable temperature.

In another preferred embodiment according to this invention, the whitelight source is configured with a single crystal phosphor (SCP) such asYAG:Ce. In one example the Ce:Y₃Al₅O₁₂ SCP can be grown by theCzochralski technique. In this embodiment according the presentinvention the SCP based on YAG:Ce is characterized by an opticalconversion efficiency of greater than 100 lumens per optical excitationwatt, of greater than 200 lumens per optical excitation watt, or evengreater than 300 lumens per optical excitation watt. Additionally, thesingle crystal YAG:Ce phosphors is characterized by a temperaturequenching characteristics above 150° C., above 200° C., or above 300° C.and a high thermal conductivity of 8-20 W/m·K to effectively dissipateheat to a heat sink member and keep the phosphor at an operabletemperature. In addition to the high thermal conductivity, high thermalquenching threshold, and high conversion efficiency, the ability toshape the phosphors into tiny forms that can act as ideal “point”sources when excited with a laser is an attractive feature.

In some embodiments the YAG:Ce can be configured to emit a yellowemission. In alternative or the same embodiments a YAG:Ce can beconfigured to emit a green emission. In yet alternative or the sameembodiments the YAG can be doped with Eu to emit a red emission. In someembodiments a LuAG is configured for emission. In alternativeembodiments, silicon nitrides or aluminum-oxi-nitrides can be used asthe crystal host materials for red, green, yellow, or blue emissions. Insome embodiments the phosphor peak emission wavelength is about 525 nm,about 540 nm, about 660 nm, or at a wavelength in between these peakwavelengths.

In an alternative embodiment, a powdered single crystal or ceramicphosphor such as a yellow phosphor or green phosphor is included. Thepowdered phosphor can be dispensed on a transparent member for atransmissive mode operation or on a solid member with a reflective layeron the back surface of the phosphor or between the phosphor and thesolid member to operate in a reflective mode. The phosphor powder may beheld together in a solid structure using a binder material wherein thebinder material is preferable in inorganic material with a high opticaldamage threshold and a favorable thermal conductivity. The phosphorpower may be comprised of colored phosphors and configured to emit awhite light when excited by and combined with the blue laser beam orexcited by a violet laser beam. The powdered phosphors could becomprised of YAG, LuAG, or other types of phosphors. In some embodimentsthe phosphor peak emission wavelength is about 525 nm, about 540 nm,about 660 nm, or at a wavelength in between these peak wavelengths.

In one embodiment of the present invention the phosphor materialcontains a yttrium aluminum garnet host material and a rare earth dopingelement, and others. In an example, the wavelength conversion element isa phosphor which contains a rare earth doping element, selected from oneof Ce, Nd, Er, Yb, Ho, Tm, Dy and Sm, combinations thereof, and thelike. In an example, the phosphor material is a high-density phosphorelement. In an example, the high-density phosphor element has a densitygreater than 90% of pure host crystal. Cerium (III)-doped YAG (YAG:Ce³⁺,or Y₃Al₅O₁₂:Ce³⁺) can be used wherein the phosphor absorbs the lightfrom the blue laser diode and emits in a broad range from greenish toreddish, with most of output in yellow. This yellow emission combinedwith the remaining blue emission gives the “white” light, which can beadjusted to color temperature as warm (yellowish) or cold (bluish)white. The yellow emission of the Ce³⁺:YAG can be tuned by substitutingthe cerium with other rare earth elements such as terbium and gadoliniumand can even be further adjusted by substituting some or all of thealuminum in the YAG with gallium. In some embodiments the phosphor peakemission wavelength is about 525 nm, about 540 nm, about 660 nm, or at awavelength in between these peak wavelengths.

In alternative examples, various phosphors can be applied to thisinvention, which include, but are not limited to organic dyes,conjugated polymers, semiconductors such as AlInGaP or InGaN, yttriumaluminum garnets (YAGs) doped with Ce³⁺ ions(Y_(1−a)Gd_(a))₃(Al_(1−b)Ga_(b))₅O₁₂:Ce³⁺, SrGa₂S₄:Eu²⁺, SrS:Eu²⁺,terbium aluminum based garnets (TAGs) (Tb₃Al₅O₅), colloidal quantum dotthin films containing CdTe, ZnS, ZnSe, ZnTe, CdSe, or CdTe.

In further alternative examples, some rare-earth doped SiAlONs can serveas phosphors. Europium(II)-doped β-SiAlON absorbs in ultraviolet andvisible light spectrum and emits intense broadband visible emission. Itsluminance and color does not change significantly with temperature, dueto the temperature-stable crystal structure. In an alternative example,green and yellow SiAlON phosphor and a red CaAlSiN₃-based (CASN)phosphor may be used.

In yet a further example, white light sources can be made by combiningnear ultraviolet emitting laser diodes with a mixture of high efficiencyeuropium based red and blue emitting phosphors plus green emittingcopper and aluminum doped zinc sulfide (ZnS:Cu,Al).

In an example, a phosphor or phosphor blend can be selected from a of(Y, Gd, Tb, Sc, Lu, La)₃(Al, Ga, In)₅O₁₂:Ce³⁺, SrGa₂S₄:Eu²⁺, SrS:Eu²⁺,and colloidal quantum dot thin films comprising CdTe, ZnS, ZnSe, ZnTe,CdSe, or CdTe. In an example, a phosphor is capable of emittingsubstantially red light, wherein the phosphor is selected from a of thegroup consisting of (Gd,Y,Lu,La)₂O₃:Eu³⁺, Bi³⁺; (Gd,Y,Lu,La)₂O₂S:Eu³⁺,Bi³⁺; (Gd,Y,Lu,La)VO₄:Eu³⁺, Bi³⁺; Y₂(O,S)₃: Eu³⁺;Ca_(1−x)Mo_(1−y)Si_(y)O₄: where 0.05<x<0.5, 0<y<0.1;(Li,Na,K)₅Eu(W,Mo)O₄; (Ca,Sr)S:Eu²⁺; SrY₂S₄:Eu²⁺; CaLa₂S₄: Ce³⁺;(Ca,Sr)S:Eu²⁺; 3.5MgO×0.5MgF₂×GeO₂:Mn⁴⁺ (MFG);(Ba,Sr,Ca)Mg_(x)P₂O₇:Eu²⁺, Mn²⁺; (Y,Lu)₂WO₆:Eu³⁺, Mo⁶⁺;(Ba,Sr,Ca)₃Mg_(x)Si₂O₈:Eu²⁺, Mn²⁺, wherein 1<x<2;(RE_(1−y)Ce_(y))Mg_(2−x)Li_(x)Si_(3−x)P_(x)O₁₂, where RE is at least oneof Sc, Lu, Gd, Y, and Tb, 0.0001<x<0.1 and 0.001<y<0.1; (Y, Gd, Lu,La)_(2−x)Eu_(x)W_(1−y)Mo_(y)O₆, where 0.5<x<1.0, 0.01<y<1.0;(SrCa)_(1−x)Eu_(x)Si₅N₈, where 0.01<x<0.3; SrZnO₂:Sm⁺³; M_(m)O_(n)X,wherein M is selected from the group of Sc, Y, a lanthanide, an alkaliearth metal and mixtures thereof; X is a halogen; 1<m<3; and 1<n<4, andwherein the lanthanide doping level can range from 0.1 to 40% spectralweight; and Eu³⁺ activated phosphate or borate phosphors; and mixturesthereof. Further details of other phosphor species and relatedtechniques can be found in U.S. Pat. No. 8,956,894, in the name ofRaring et al. issued Feb. 17, 2015, and titled “White light devicesusing non-polar or semipolar gallium containing materials andphosphors”, which is commonly owned, and hereby incorporated byreference herein.

In some embodiments of the present invention, ceramic phosphor materialsare embedded in a binder material such as silicone. This configurationis typically less desirable because the binder materials often have poorthermal conductivity, and thus get very hot wherein the rapidly degradeand even burn. Such “embedded” phosphors are often used in dynamicphosphor applications such as color wheels where the spinning wheelcools the phosphor and spreads the excitation spot around the phosphorin a radial pattern.

Sufficient heat dissipation from the phosphor is a critical designconsideration for the integrated white light source based on laser diodeexcitation. Specifically, the optically pumped phosphor system hassources of loss in the phosphor that result is thermal energy and hencemust be dissipated to a heat-sink for optimal performance. The twoprimary sources of loss are the Stokes loss which is a result ofconverting photons of higher energy to photons of lower energy such thatdifference in energy is a resulting loss of the system and is dissipatedin the form of heat. Additionally, the quantum efficiency or quantumyield measuring the fraction of absorbed photons that are successfullyre-emitted is not unity such that there is heat generation from otherinternal absorption processes related to the non-converted photons.Depending on the excitation wavelength and the converted wavelength, theStokes loss can lead to greater than 10%, greater than 20%, and greaterthan 30%, and greater loss of the incident optical power to result inthermal power that must be dissipated. The quantum losses can lead to anadditional 10%, greater than 20%, and greater than 30%, and greater ofthe incident optical power to result in thermal power that must bedissipated. With laser beam powers in the 1 W to 100 W range focused tospot sizes of less than 1 mm in diameter, less than 500 μm in diameter,or even less than 100 μm in diameter, power densities of over 1 W/mm²,100 W/mm², or even over 2,500 W/mm² can be generated. As an example,assuming that the spectrum is comprised of 30% of the blue pump lightand 70% of the converted yellow light and a best case scenario on Stokesand quantum losses, we can compute the dissipated power density in theform of heat for a 10% total loss in the phosphor at 0.1 W/mm², 10W/mm², or even over 250 W/mm². Thus, even for this best-case scenarioexample, this is a tremendous amount of heat to dissipate. This heatgenerated within the phosphor under the high intensity laser excitationcan limit the phosphor conversion performance, color quality, andlifetime.

For optimal phosphor performance and lifetime, not only should thephosphor material itself have a high thermal conductivity, but it shouldalso be attached to the submount or common support member with a highthermal conductivity joint to transmit the heat away from the phosphorand to a heat-sink. In this invention, the phosphor is either attachedto the common support member as the laser diode as in the CPoS or isattached to an intermediate submount member that is subsequentlyattached to the common support member. Candidate materials for thecommon support member or intermediate submount member are SiC, AlN, BeO,diamond, copper, copper tungsten, sapphire, aluminum, or others. Theinterface joining the phosphor to the submount member or common supportmember must be carefully considered. The joining material should becomprised of a high thermal conductivity material such as solder (orother) and be substantially free from voids or other defects that canimpede heat flow. In some embodiments, glue materials can be used tofasten the phosphor. Ideally the phosphor bond interface will have asubstantially large area with a flat surface on both the phosphor sideand the support member sides of the interface.

In the present invention, the laser diode output beam must be configuredto be incident on the phosphor material to excite the phosphor. In someembodiments the laser beam may be directly incident on the phosphor andin other embodiments the laser beam may interact with an optic,reflector, waveguide, or other object to manipulate the beam prior toincidence on the phosphor. Examples of such optics include, but are notlimited to ball lenses, aspheric collimator, aspheric lens, fast or slowaxis collimators, dichroic mirrors, turning mirrors, optical isolators,but could be others.

In some embodiments, the apparatus typically has a free space with anon-guided laser beam characteristic transmitting the emission of thelaser beam from the laser device to the phosphor material. The laserbeam spectral width, wavelength, size, shape, intensity, andpolarization are configured to excite the phosphor material. The beamcan be configured by positioning it at the precise distance from thephosphor to exploit the beam divergence properties of the laser diodeand achieve the desired spot size. In one embodiment, the incident anglefrom the laser to the phosphor is optimized to achieve a desired beamshape on the phosphor. For example, due to the asymmetry of the laseraperture and the different divergent angles on the fast and slow axis ofthe beam the spot on the phosphor produced from a laser that isconfigured normal to the phosphor would be elliptical in shape,typically with the fast axis diameter being larger than the slow axisdiameter. To compensate this, the laser beam incident angle on thephosphor can be optimized to stretch the beam in the slow axis directionsuch that the beam is more circular on phosphor. In other embodimentsfree space optics such as collimating lenses can be used to shape thebeam prior to incidence on the phosphor. The beam can be characterizedby a polarization purity of greater than 50% and less than 100%. As usedherein, the term “polarization purity” means greater than 50% of theemitted electromagnetic radiation is in a substantially similarpolarization state such as the transverse electric (TE) or transversemagnetic (TM) polarization states, but can have other meaningsconsistent with ordinary meaning.

The white light apparatus also has an electrical input interfaceconfigured to couple electrical input power to the laser diode device togenerate the laser beam and excite the phosphor material. In an example,the laser beam incident on the phosphor has a power of less than 0.1 W,greater than 0.1 W, greater than 0.5 W, greater than 1 W, greater than 5W, greater than 10 W, or greater than 20 W. The white light sourceconfigured to produce greater than 1 lumen, 10 lumens, 100 lumens, 1000lumens, 10,000 lumens, or greater of white light output.

The support member is configured to transport thermal energy from the atleast one laser diode device and the phosphor material to a heat sink.The support member is configured to provide thermal impedance of lessthan 10 degrees Celsius per watt, less than 5 degrees Celsius per watt,or less than 3 degrees Celsius per watt of dissipated powercharacterizing a thermal path from the laser device to a heat sink. Thesupport member is comprised of a thermally conductive material such ascopper with a thermal conductivity of about 400 W/(m-K), aluminum with athermal conductivity of about 200 W/(mK), 4H—SiC with a thermalconductivity of about 370 W/(m-K), 6H—SiC with a thermal conductivity ofabout 490 W/(m-K), AlN with a thermal conductivity of about 230 W/(m-K),a synthetic diamond with a thermal conductivity of about >1000 W/(m-K),sapphire, or other metals, ceramics, or semiconductors. The supportmember may be formed from a growth process such as SiC, AlN, orsynthetic diamond, and then mechanically shaped by machining, cutting,trimming, or molding. Alternatively, the support member may be formedfrom a metal such as copper, copper tungsten, aluminum, or other bymachining, cutting, trimming, or molding.

Currently, solid state lighting is dominated by systems utilizing blueor violet emitting light emitting diodes (LEDs) to excite phosphorswhich emit a broader spectrum. The combined spectrum of the so-calledpump LEDs and the phosphors can be optimized to yield white lightspectra with controllable color point and good color rendering index.Peak wall plug efficiencies for state of the art LEDs are quite high,above 70%, such that LED based white lightbulbs are now the leadinglighting technology for luminous efficacy. As laser light sources,especially high-power blue laser diodes made from gallium and nitrogencontaining material based novel manufacture processes, have shown manyadvantageous functions on quantum efficiency, power density, modulationrate, surface brightness over conventional LEDs. This opens up theopportunity to use lighting fixtures, lighting systems, displays,projectors and the like based on solid-state light sources as a means oftransmitting information with high bandwidth using visible light. Italso enables utilizing the modulated laser signal or direct laser lightspot manipulation to measure and or interact with the surroundingenvironment, transmit data to other electronic systems and responddynamically to inputs from various sensors. Such applications are hereinreferred to as “smart lighting” applications.

In some embodiments, the present invention provides novel uses andconfigurations of gallium and nitrogen containing laser diodes incommunication systems such as visible light communication systems. Morespecifically the present invention provides communication systemsrelated to smart lighting applications with gallium and nitrogen basedlasers light sources coupled to one or more sensors with a feedback loopor control circuitry to trigger the light source to react with one ormore predetermined responses and combinations of smart lighting andvisible light communication. In these systems, light is generated usinglaser devices which are powered by one or more laser drivers. In someembodiments, individual laser devices are used and optical elements areprovided to combine the red, green and blue spectra into a white lightspectrum. In other embodiments, blue or violet laser light is providedby a laser source and is partially or fully converted by a wavelengthconverting element into a broader spectrum of longer wavelength lightsuch that a white light spectrum is produced.

The blue or violet laser devices illuminate a wavelength convertingelement which absorbs part of the pump light and reemits a broaderspectrum of longer wavelength light. The light absorbed by thewavelength converting element is referred to as the “pump” light. Thelight engine is configured such that some portion of both light from thewavelength converting element and the unconverted pump light are emittedfrom the light-engine. When the non-converted, blue pump light and thelonger wavelength light emitted by the wavelength converting element arecombined, they may form a white light spectrum. In an example, thepartially converted light emitted generated in the wavelength conversionelement results in a color point, which is white in appearance. In anexample, the color point of the white light is located on the Planckianblackbody locus of points. In an example, the color point of the whitelight is located within du′v′ of less than 0.010 of the Planckianblackbody locus of points. In an example, the color point of the whitelight is preferably located within du′v′ of less than 0.03 of thePlanckian blackbody locus of points.

In an example, the wavelength conversion element is a phosphor whichcontains garnet host material and a doping element. In an example, thewavelength conversion element is a phosphor, which contains an yttriumaluminum garnet host material and a rare earth doping element, andothers. In an example, the wavelength conversion element is a phosphorwhich contains a rare earth doping element, selected from one or more ofNd, Cr, Er, Yb, Nd, Ho, Tm Cr, Dy, Sm, Tb and Ce, combinations thereof,and the like. In an example, the wavelength conversion element is aphosphor which contains oxy-nitrides containing one or more of Ca, Sr,Ba, Si, Al with or without rare-earth doping. In an example, thewavelength conversion element is a phosphor which contains alkalineearth silicates such as M₂SiO₄:Eu²⁺ (where M is one or more of Ba²⁺,Sr²⁺ and Ca²⁺). In an example, the wavelength conversion element is aphosphor which contains Sr₂LaAlO₅:Ce³⁺, Sr₃SiO₅:Ce³⁺ or Mn⁴⁺-dopedfluoride phosphors. In an example, the wavelength conversion element isa high-density phosphor element. In an example, the wavelengthconversion element is a high-density phosphor element with densitygreater than 90% of pure host crystal. In an example, the wavelengthconverting material is a powder. In an example, the wavelengthconverting material is a powder suspended or embedded in a glass,ceramic or polymer matrix. In an example, the wavelength convertingmaterial is a single crystalline member. In an example, the wavelengthconverting material is a powder sintered to density of greater than 75%of the fully dense material. In an example, the wavelength convertingmaterial is a sintered mix of powders with varying composition and/orindex of refraction. In an example, the wavelength converting element isone or more species of phosphor powder or granules suspended in a glassyor polymer matrix. In an example, the wavelength conversion element is asemiconductor. In an example, the wavelength conversion element containsquantum dots of semiconducting material. In an example, the wavelengthconversion element is comprised by semiconducting powder or granules.

For laser diodes the phosphor may be remote from the laser die, enablingthe phosphor to be well heat sunk, enabling high input power density.This is an advantageous configuration relative to LEDs, where thephosphor is typically in contact with the LED die. While remote-phosphorLEDs do exist, because of the large area and wide emission angle ofLEDs, remote phosphors for LEDs have the disadvantage of requiringsignificantly larger volumes of phosphor to efficiently absorb andconvert all of the LED light, resulting in white light emitters withlarge emitting areas and low luminance.

For LEDs, the phosphor emits back into the LED die where the light fromthe phosphor can be lost due to absorption. For laser diode modules, theenvironment of the phosphor can be independently tailored to result inhigh efficiency with little or no added cost. Phosphor optimization forlaser diode modules can include highly transparent, non-scattering,ceramic phosphor plates. Decreased temperature sensitivity can bedetermined by doping levels. A reflector can be added to the backside ofa ceramic phosphor, reducing loss. The phosphor can be shaped toincrease in-coupling and reduce back reflections. Of course, there canbe additional variations, modifications, and alternatives.

For laser diodes, the phosphor or wavelength converting element can beoperated in either a transmission or reflection mode. In a transmissionmode, the laser light is shown through the wavelength convertingelement. The white light spectrum from a transmission mode device is thecombination of laser light not absorbed by the phosphor and the spectrumemitted by the wavelength converting element. In a reflection mode, thelaser light is incident on the first surface of the wavelengthconverting element. Some fraction of the laser light is reflected off ofthe first surface by a combination of specular and diffuse reflection.Some fraction of the laser light enters the phosphor and is absorbed andconverted into longer wavelength light. The white light spectrum emittedby the reflection mode device is comprised by the spectrum from thewavelength converting element, the fraction of the laser light diffuselyreflected from the first surface of the wavelength converting elementand any laser light scattered from the interior of the wavelengthconverting element.

In a specific embodiment, the laser light illuminates the wavelengthconverting element in a reflection mode. That is, the laser light isincident on and collected from the same side of the wavelengthconverting element. The element may be heat sunk to the emitter packageor actively cooled. Rough surface is for scattering and smooth surfaceis for specular reflection. In some cases such as with a single crystalphosphor a rough surface with or without an AR coating of the wavelengthconverting element is provided to get majority of excitation light intophosphor for conversion and Lambertian emission while scattering some ofthe excitation light from the surface with a similar Lambertian as theemitted converted light. In other embodiments such as ceramic phosphorswith internal built-in scattering centers are used as the wavelengthconverting elements, a smooth surface is provided to allow all laserexcitation light into the phosphor where blue and wavelength convertedlight exits with a similar Lambertian pattern.

In a specific embodiment, the laser light illuminates the wavelengthconverting element in a transmission mode. That is, the laser light isincident on one side of the element, traverses through the phosphor, ispartially absorbed by the element and is collected from the oppositeside of the phosphor.

The wavelength converting elements, in general, can themselves containscattering elements. When laser light is absorbed by the wavelengthconverting element, the longer wavelength light that is emitted by theelement is emitted across a broad range of directions. In bothtransmission and reflection modes, the incident laser light must bescattered into a similar angular distribution in order to ensure thatthe resulting white light spectrum is substantially the same when viewedfrom all points on the collecting optical elements. Scattering elementsmay be added to the wavelength converting element in order to ensure thelaser light is sufficiently scattered. Such scattering elements mayinclude: low index inclusions such as voids, spatial variation in theoptical index of the wavelength converting element which could beprovided as an example by suspending particles of phosphor in a matrixof a different index or sintering particles of differing composition andrefractive index together, texturing of the first or second surface ofthe wavelength converting element, and the like.

In a specific embodiment, a laser or SLED driver module is provided. Forexample, the laser driver module generates a drive current, with thedrive currents being adapted to drive a laser diode to transmit one ormore signals such as digitally encoded frames of images, digital oranalog encodings of audio and video recordings or any sequences ofbinary values. In a specific embodiment, the laser driver module isconfigured to generate pulse-modulated light signals at a modulationfrequency range of about 50 MHz to 300 MHz, 300 MHz to 1 GHz or 1 GHz to100 GHz. In another embodiment the laser driver module is configured togenerate multiple, independent pulse-modulated light signal at amodulation frequency range of about 50 MHz to 300 MHz, 300 MHz to 1 GHzor 1 GHz to 100 GHz. In an embodiment, the laser driver signal can bemodulated by an analog voltage or current signal.

Some embodiments of the present invention provide a light sourceconfigured for emission of laser based visible light such as white lightand an infrared light, to form an illumination source capable ofproviding visible and IR illumination. The light source includes agallium and nitrogen containing laser diode excitation source configuredwith an optical cavity. The optical cavity includes an optical waveguideregion and one or more facet regions. The optical cavity is configuredwith electrodes to supply a first driving current to the gallium andnitrogen containing material. The first driving current provides anoptical gain to an electromagnetic radiation propagating in the opticalwaveguide region of the gallium and nitrogen containing material. Theelectromagnetic radiation is outputted through at least one of the oneor more facet regions as a directional electromagnetic radiationcharacterized by a first peak wavelength in the ultra-violet, blue,green, or red wavelength regime. Furthermore, the light source includesa wavelength converter, such as a phosphor member, optically coupled tothe electromagnet radiation pathway to receive the directionalelectromagnetic radiation from the excitation source. The wavelengthconverter is configured to convert at least a fraction of thedirectional electromagnetic radiation with the first peak wavelength toat least a second peak wavelength that is longer than the first peakwavelength. In a preferred embodiment the output is comprised of awhite-color spectrum with at least the second peak wavelength andpartially the first peak wavelength forming the laser based visiblelight spectrum component according to the present invention. In oneexample, the first peak wavelength is a blue wavelength and the secondpeak wavelength is a yellow wavelength. The light source optionallyincludes a beam shaper configured to direct the white-color spectrum forilluminating a target or area of interest.

In one embodiment of the present invention a laser diode or lightemitting diode with a third peak wavelength is included to form the IRemission component of the dual band emitting light source. The IR laserdiode contains an optical cavity configured with electrodes to supply asecond driving current configured to the IR laser diode. The seconddriving current provides an optical gain to an electromagnetic radiationpropagating in the optical waveguide region of the IR laser diodematerial. The electromagnetic radiation is outputted through at leastone of the one or more facet regions as a directional electromagneticradiation characterized by a third peak wavelength in the IR regime. Inone configuration the directional IR emission is optically coupled tothe wavelength converter member such that the wavelength convertermember is within the optical pathway of the IR emission to receive thedirectional electromagnetic radiation from the excitation source. Onceincident on the wavelength converter member, the IR emission with thethird peak wavelength would be at least partially reflected from thewavelength converter member and redirected into the same optical pathwayas the white light emission with the first and second peak wavelengths.The IR emission would be directed through the optional beam shaperconfigured to direct the output IR light for illuminating approximatelythe same target or area of interest as the visible light. In thisembodiment the first and second driving current could be activatedindependently such that the apparatus could provide a visible lightsource with only the first driving current activated, an IR light sourcewith the second driving current activated, or could simultaneouslyprovide both a visible and IR light source. In some applications itwould be desirable to only use the IR illumination source for IRdetection. Once an object was detected, the visible light source couldbe activated.

FIG. 10A is a functional block diagram for a laser-based white lightsource containing a gallium and nitrogen containing violet or blue pumplaser and a wavelength converting element to generate a white lightemission, and an infrared emitting laser diode to generate an IRemission according to an embodiment of the present invention. Referringto FIG. 10A, a violet or blue laser device emitting a spectrum with acenter point wavelength between 390 and 480 nm is provided. The lightfrom the violet or blue laser device is incident on a wavelengthconverting element, which partially or fully converts the blue lightinto a broader spectrum of longer wavelength light such that a whitelight spectrum is produced. In some embodiments the gallium and nitrogencontaining laser diode operates in the 480 nm to 540 nm range. In someembodiments the laser diode is comprised from a III-nitride materialemitting in the ultraviolet region with a wavelength of about 270 nm toabout 390 nm. A laser driver is provided which powers the gallium andnitrogen containing laser device to excite the visible emittingwavelength member. In some embodiments, one or more beam shaping opticalelements may be provided in order to shape or focus the white lightspectrum. Additionally, an IR emitting laser device is included togenerate an IR illumination. The directional IR electromagneticradiation from the laser diode is incident on the wavelength convertingelement wherein it is reflected from or transmitted through thewavelength converting element such that it follows the same optical pathas the white light emission. The IR emission could include a peakwavelength in the 700 nm to 1100 nm range based on gallium and arsenicmaterial system (e.g., GaAs) for near-IR illumination, or a peakwavelength in the 1100 to 2500 nm range based on an indium andphosphorous containing material system (e.g., InP) for eye-safewavelength IR illumination, or in the 2500 nm to 15000 nm wavelengthrange based on quantum cascade laser technology for mid-IR thermalimaging. For example, GaInAs/AlInAs quantum cascade lasers operate atroom temperature in the wavelength range of 3 μm to 8μm. A laser driveis included to power the IR emitting laser diode and deliver acontrolled amount of current at a sufficiently high voltage to operatethe IR laser diode. Optionally, the one or more beam shaping opticalelements can be one selected from slow axis collimating lens, fast axiscollimating lens, aspheric lens, ball lens, total internal reflector(TIR) optics, parabolic lens optics, refractive optics, or a combinationof above. In other embodiments, the one or more beam shaping opticalelements can be disposed prior to the laser light incident to thewavelength converting element.

In some embodiments the visible and/or IR emission from the light sourceare coupled into an optical waveguide such as an optical fiber, whichcould be a glass optical fiber or a plastic optical fiber. The opticalfiber of an arbitrary length, including a single mode fiber (SMF) or amulti-mode fiber (MMF), with core diameters ranging from about 1 μm to10 μm, about 10 μm to 50 μm, about 50 μm to 150 μm, about 150 μm to 500μm, about 500 μm to 1 mm, about 1 mm to 5 mm or greater than 5 mm. Theoptical fiber is aligned with a collimation optics member to receive thecollimated white light and/or IR emission.

In an additional configuration of the present embodiment that includes adirect laser diode IR illumination source, the IR illumination isoptically coupled directly to the optical beam shaping elements ratherthan interacting with the wavelength converter element where it would bereflected and/or transmitted. FIG. 10B is a functional block diagram fora laser-based white light source containing a gallium and nitrogencontaining violet or blue pump laser and a wavelength converting elementto generate a white light emission, and an infrared emitting laser diodeto generate an IR emission according to an embodiment of the presentinvention. In some embodiments, the white light source is used as a“light engine” for VLC or smart lighting applications. Referring to FIG.10B, a blue or violet laser device emitting a spectrum with a centerpoint wavelength between 390 and 480 nm is provided. In some embodimentsthe gallium and nitrogen containing laser diode operates in the 480 nmto 540 nm range. In some embodiments the laser diode is comprised from aIII-nitride material emitting in the ultraviolet region with awavelength of about 270 nm to about 390 nm. The light from the violet orblue laser device is incident on a wavelength converting element, whichpartially or fully converts the blue light into a broader spectrum oflonger wavelength light such that a white light spectrum is produced. Alaser driver is provided which powers the gallium and nitrogencontaining laser device. In some embodiments, one or more beam shapingoptical elements may be provided in order to shape or focus the whitelight spectrum. Additionally, an IR emitting laser device is included togenerate an IR illumination. The directional IR electromagneticradiation from the laser diode is directly optically coupled to the beamshaper elements, avoiding interactions with the wavelength converterelement. The IR emission could include a peak wavelength in the 700 nmto 1100 nm range based on gallium and arsenic material system (e.g.,GaAs) for near-IR illumination, or a peak wavelength in the 1100 to 2500nm range based on an indium and phosphorous containing material system(e.g., InP) for eye-safe wavelength IR illumination, or in the 2500 nmto 15000 nm wavelength range based on quantum cascade laser technologyfor mid-IR thermal imaging. For example, GaInAs/AlInAs quantum cascadelasers operate at room temperature in the wavelength range of 3 μm to8μm. A laser drive is included to power the IR emitting laser diode.Optionally, the one or more beam shaping optical elements can be oneselected from slow axis collimating lens, fast axis collimating lens,aspheric lens, ball lens, total internal reflector (TIR) optics,parabolic lens optics, refractive optics, or a combination of above. Inother embodiments, the one or more beam shaping optical elements can bedisposed prior to the laser light incident to the wavelength convertingelement.

In some embodiments the visible and/or IR emission from the light sourceare coupled into an optical waveguide such as an optical fiber, whichcould be a glass optical fiber or a plastic optical fiber. The opticalfiber of an arbitrary length, including a single mode fiber (SMF) or amulti-mode fiber (MMF), with core diameters ranging from about 1 μm to10 μm, about 10 μm to 50 μm, about 50 μm to 150 μm, about 150 μm to 500μm, about 500 μm to 1 mm, about 1 mm to 5 mm or greater than 5 mm. Theoptical fiber is aligned with a collimation optics member to receive thecollimated white light and/or IR emission.

The resulting spectrum from the embodiment described in FIGS. 10A and10B according to the present invention would be comprised of arelatively narrow band (about 0.5 to 3 nm) emission spectrum from thegallium and nitrogen containing laser diode in the UV or blue wavelengthregion, a broadband (about 10 to 100 nm) wavelength converter emissionin the visible spectrum with a longer peak wavelength than the UV orblue laser diode, and the relatively narrow band (about 1 to 10 nm)emission from the IR laser diode with a longer wavelength than the peakemission wavelength from the visible phosphor member. FIG. 10C presentsan example optical spectrum according to the present invention. In thisfigure, the gallium and nitrogen containing laser diode emits in theblue region at about 440 to 455 nm, the visible wavelength convertermember emits in the yellow region, and the included IR illuminationlaser diode emits at 875 nm. Of course, there can be many otherconfigurations of the present invention, including different wavelengthemitting gallium and nitrogen containing laser diodes, differentwavelength visible phosphor emission, and different wavelength IR laserdiode peak emission wavelengths. For example, the IR laser diode couldoperate with a peak wavelength of between 700 nm and 3 μm.

The IR lasers according to the present invention could be configured toemit at wavelengths between 700 nm and 2.5 microns. The IR laser diodecan be used to provide an IR illumination function or a LiFi/VLCcommunication function, or a combination of both functions. For example,a laser diode emitting in the 700 nm to 1100 nm range based on GaAs forNIR night vision illumination, range finding and LIDAR sensing, andcommunication could be included. In another example a laser diodeoperating in the 1100 to 2500 nm range based on InP for eye-safewavelength IR illumination, range finding, LIDAR sensing, andcommunication could be included. In yet another example, a laser diodeoperating the in 2500 nm to 15000 nm wavelength range based on quantumcascade laser technology for mid-IR thermal imaging, sensing, andcommunication could be included. For example, GaInAs/AlInAs quantumcascade lasers operate at room temperature in the wavelength range of 3μm to 8μm. IR laser diode devices according to the present inventioncould be formed on InP substrates using the InGaAsP material system orformed on GaAs substrates using the InAlGaAsP. Quantum cascade laserscan be included for IR emission. In one embodiment one or more IR laserdevices could be formed on the same carrier wafer as the visible violetor blue GaN laser diode source using the epitaxy transfer technologyaccording to this invention. Such a device would be advantageous for IRillumination since it could be low cost, compact, and have similaremission aperture location as the visible laser diode to effectivelysuperimpose the IR emission and the visible light emission.Additionally, such a device would be advantageous in communicationapplications as the IR laser diode, while not adding to the luminousefficacy of the light engine, would provide a non-visible channel forcommunications. This would allow for data transfer to continue under abroader range of conditions. For example, a VLC-enabled light engineusing only visible emitters would be incapable of effectivelytransmitting data when the light source is nominally turned off as onewould find in, for example, a movie theater, conference room during apresentation, a moodily lit restaurant or bar, or a bed-room at nightamong others. In another example, the non-converted laser device mightemit a spectrum corresponding to blue or violet light, with a centerwavelength between 390 and 480 nm. In some embodiments the gallium andnitrogen containing laser diode operates in the 480 nm to 540 nm range,or can operate in the UV range from about 270 nm to 390 nm. In anotherembodiment, the non-converted blue or violet laser may either be notincident on the wavelength converting element and combined with thewhite light spectrum in beam shaping and combining optics. In someembodiments the visible and/or IR emission from the light source arecoupled into an optical waveguide such as an optical fiber, which couldbe a glass optical fiber or a plastic optical fiber.

In a second embodiment of the present invention a second wavelengthconverter element member is included to provide an emission in the IRregime at a third peak wavelength, to provide the IR emission componentof the dual band emitting light source. The IR wavelength convertermember, such as a phosphor member, is configured to receive and absorb alaser induced pump light and emit a longer wavelength IR light. In thisembodiment, the dual band light source comprises the first wavelengthconverter member for emitting visible light and the second wavelengthconverter member for emitting IR light.

Typically, the difference in the down converters from LED to Laser isthe change from a powder phosphor solution in a silicone binder matrix,to solid body phosphors of single crystals, sintered, hybrids andphosphors in Glass. The solid body phosphor is generally required toreduce the extreme heat generation under blue laser excitation in asmall, controlled spot.

Extending the usable wavelength range for laser-based lighting, it ispossible to use Infrared down-converting phosphors to generate emissionin the NIR (0.7-1.4 μm) and mid-IR (1.4-3.0 μm) spectrum, or into thedeeper IR of beyond 3.0 μm. This could be purely IR emission, or acombination of visible and infrared emission depending on applicationrequirements. A large number of potential IR phosphors exist, but theirsuitability depends on the application wavelength, and the phosphorsinherent properties for conversion of visible light to IR light. IN someembodiments the phosphor emission is characterized by a 1550 nmphotoluminescence peak wavelength emission associated with the Er⁺³ ion4f-4 intraband transition.

Some examples of phosphor materials that produce infrared light emissioninclude Lu₃Al₅O₁₂: 0.05 Ce³⁺, 0.5% Cr³⁺ emitting in the 500-850 nmrange, La3Ga_(4.95)GeO₁₄:0.05 Cr³⁺ emitting in the 600-1200 nm range,Bi-doped GeO2 glass emitting in the 1000-1600 nm range,Ca₂LuZr₂Al₃O₁₂:0.08 Cr³⁺ emitting in the 650-850 nm range, ScBO₃:0.02Cr³⁺ emitting in the 700-950 nm range, YAl₃(BO₃)₄:0.04 Cr³⁺, 0.01 Yb³⁺emitting in the 650-850 nm and 980 nm range, and NaScSi₂O₆: 0.06 Cr³⁺emitting in the 750-950 nm range.

Additionally, a large body of work for infrared phosphors has centeredaround the use of Cr³⁺ materials. For example, ZnGa₂O₄ emitting in the650-750 nm range, Zn(Ga_(1-x)Al_(x))₂O₄ emitting in the 675-800 nmrange, ZnxGa₂O_(3+x) emitting in the 650-750 nm range, MgGa₂O₄ emittingin the 650-770 nm range, Zn₃Ga₂Ge₂O₁₀ emitting in the 650-1000 nm range,Zn_(1+x)Ga_(2−2x)(Ge, Sn)_(x)O₄ emitting in the 650-800 nm range,Zn₃Ga₂Ge₂O₁₀ emitting in the 600-800 nm range, Zn₃Ga₂Sn₁O₈ emitting inthe 600-800 nm range, Ca₃Ga₂Ge₃O₁₂ emitting in the 670-1100 nm range,Ca₁₄Zn₆Al₁₀O₃₅ emitting in the 650-750 nm range, Y₃Al₂Ga₃O₁₀ emitting inthe 500-800 nm range, Gd₃Ga₅O₁₀ emitting in the 650-800 nm range,Lu₃Al₅O₁₂ emitting in the 500-850 nm range, La₃Ga₅GeO₁₄ emitting in the600-1200 nm range, LiGa₅O₈ emitting in the 650-850 nm range, β-Ga₂O₃emitting in the 650-850 nm range, and SrGa₁₂O₁₉ emitting in the 650-950nm range.

In some embodiments according to the present invention the IR wavelengthconverter members are comprised of semiconductor materials. In oneexample solid state structures employing semiconductor bulk materialstructures, quantum well structures, or quantum wire structuresconfigured to emit infrared light are included. Some examples of suchsolid structures capable of emitting IR electromagnetic radiationinclude, Si emitting in the 700-1000 nm range, Ge emitting in the800-2000 nm range, GaAs emitting in the 800-900 nm range, InP emittingin the 800-900 nm range, InGaAs emitting in the 900-1700 nm range, InAsemitting in the 2000-3000 nm range, InAlAs emitting in the 900-1600 nmrange, AlGaAs emitting in the 700-900 nm range, AlInGaP emitting in the600-800 nm range, InGaAsP emitting in the 1200-1800 nm range, InGaAsSbemitting in the 1800-3500 nm range, GaSb in the 1000-1300 nm range,GaInSb emitting in the 1600-1900 nm range, InSb emitting in the2500-3000 nm range, CdTe emitting in the 700-800 nm range, HgTe emittingin the 3800-5000 nm range, [Hg_(x)Cd_(1-x)]Te emitting in the 700-5000nm range.

Alternatively, infrared emitting quantum dot materials of the propersize can be incorporated as wavelength converter members in the presentinvention. Some examples of materials choices for infrared emittingquantum dots are Si emitting in the 700-1000 nm range, Ge emitting inthe 800-2000 nm range, GeSn emitting in the 800-1500 nm range, PbSemitting in the 700-2000 nm range, PbSe emitting in the 800-5000 nmrange, PbTe emitting in the 900-3000 nm range, InAs emitting in the750-3000 nm range, InSb emitting in the 1000-2500 nm range, HgTeemitting in the 1000-5000 nm range, Ag2S emitting in the 700-1500 nmrange, Ag₂Se emitting in the 900-2000 nm range, CuInSe₂ emitting in the650-1500 nm range, AgInSe₂ emitting in the 600-900 nm range, andCs_(1-x)FA_(x)PbI₃ emitting in the 650-850 nm range, but of course therecould be others.

In order to incorporate IR emitting phosphors in a blue/near UVlaser-based device, a number of conditions should be met.

IR Phosphor fluoresces under laser emission wavelengths of near UVand/or Blue (e.g., 380 nm-480 nm).

IR phosphor fluoresces under secondary emission from visible emittingphosphors in device (e.g., 480 nm-700 nm). This reduces the stokes shiftlosses as compared to direct laser fluorescence, thereby reducingheating of the IR phosphor.

IR phosphor can be incorporated into a solid body element such as asingle crystal, sintered, hybrid, or phosphor in glass structure. Thisstructure could be composed of both Visible and IR emitting phosphormaterials, or as separate structures.

The IR phosphor member can be comprised of different solid or powdermicro-structures and configured for excitation by the laser diodeexcitation source. In some embodiments the phosphors would be configuredwith coating layers to modify the reflectivity of the excitation lightand/or modify the reflectivity of the IR phosphor emission, and/ormodify the reflectivity of the visible phosphor emission. In one exampleaccording to this invention, the phosphor would contain anantireflective coating layer on the excitation surface configured toreduce the reflectivity of the excitation beam such that it can be moreefficiently converted to IR or visible light within the phosphor member.Such coating layers could be comprised of dielectric layers such assilicon dioxide, tantalum pentoxide, hafnia, aluminum oxide, siliconnitride, or others. In some embodiments the phosphor surface isintentionally roughened or patterned to reduce the reflectivity andinduce an optical scattering effect.

In another example according to this invention, the phosphor isconfigured for a transmission mode operation wherein the excitationsurface and the emission surface would be on opposite sides or faces ofthe phosphor. In this configuration, the phosphor could have anantireflective coating layer on the emission surface configured toreduce the reflectivity of the IR phosphor emission such that it canmore efficiently exit the phosphor member as useful IR emission from theemission surface. Such coating reflectivity reducing layers could becomprised of dielectric layers such as silicon dioxide, tantalumpentoxide, hafnia, aluminum oxide, silicon nitride, or others. In someembodiments the phosphor surface is intentionally roughened or patternedto reduce the reflectivity and induce an optical scattering effect.

In another example according to this invention, the phosphor isconfigured for a reflective mode operation wherein the excitation beamis incident on the emission surface such that emission and excitation ofthe phosphor takes place on the same side or face of the phosphormember. In this configuration, the phosphor could have an antireflectivecoating layer on the emission surface configured to reduce thereflectivity of the IR phosphor emission such that it can moreefficiently exit the phosphor member and/or reduce the reflectivity ofthe excitation light such that it can more efficiently penetrate intothe phosphor where it can be converted to useful IR emission. Suchcoating layers could be comprised of dielectric layers such as silicondioxide, tantalum pentoxide, hafnia, aluminum oxide, silicon nitride, orothers. Moreover, in some embodiments comprised of a reflection modephosphor the backside or bottom side of the phosphor member would beconfigured with a highly reflective coating or layer. The reflectivecoating would function to reflect the IR emitted light generated in thephosphor off the back surface so that it can be usefully emitted throughthe top or front side emission surface. The reflective coating couldalso be configured to reflect the excitation light. Such reflectivecoating layers could be comprised of metals such as Ag, Al, or others,or could be comprised of dielectric layers such as distributed Braggreflector (DBR) stacks.

FIG. 11 provides schematic diagrams of different IR phosphor members. InFIG. 11A a single crystal phosphor member is configured for reflectivemode operation. Single crystal phosphors can offer performance benefitssuch as high thermal conductivity to enable operation at hightemperature and excitation density. The single crystal phosphor in FIG.11 a is contains a reflective mirror on the back or bottom side of thephosphor. The mirror stack can also be designed for a soldering attachprocess wherein diffusion barrier layers can be included to preventdamage to the mirror layer when the single crystal IR phosphor member isattached to a package or support member. The reflective mode singlecrystal phosphor of FIG. 11A is configured with an anti-reflectivecoating and/or a roughening or patterning of the top side emissionsurface.

In FIG. 11B a phosphor in glass member is configured for reflective modeoperation. Such phosphor in glass structures can offer performancebenefits such as high optical scattering of the excitation emission andthe phosphor emission to control and contain the emission area, whileoffering acceptable thermal conductivity for operation at hightemperature and excitation density. The phosphor in glass structure inFIG. 11A is contains a reflective mirror on the back or bottom side ofthe phosphor. The mirror stack can also be designed for a solderingattach process wherein diffusion barrier layers can be included toprevent damage to the mirror layer when the phosphor in glass IRphosphor member is attached to a package or support member. Thereflective mode phosphor in glass structure of FIG. 11B is configuredwith an anti-reflective coating and/or a roughening or patterning of thetop side emission surface.

In FIG. 11C a sintered powder or ceramic phosphor is configured forreflective mode operation. Such sintered powder or ceramic phosphorstructures can offer performance benefits such as high opticalscattering of the excitation emission and the phosphor emission tocontrol and contain the emission area, while offering acceptable thermalconductivity for operation at high temperature and excitation density.The sintered powder or ceramic phosphor in FIG. 11C is contains areflective mirror on the back or bottom side of the phosphor. The mirrorstack can also be designed for a soldering attach process whereindiffusion barrier layers can be included to prevent damage to the mirrorlayer when the sintered powder or ceramic IR phosphor member is attachedto a package or support member. The reflective mode sintered powder orceramic phosphor structure of FIG. 11C is configured with ananti-reflective coating and/or a roughening or patterning of the topside emission surface.

When integrating the IR emitting phosphor member with the laser basedwhite light illumination source there are multiple arrangements that thevisible emitting and IR emitting phosphor members can be configured withrespect to each other. The examples provided in this application are notintended to coverall all such arrangements and shall not limit the scopeof the present invention, because of course there could be otherarrangements and architectures. Perhaps the most simple example phosphorarrangement would have the first and second wavelength converter membersconfigured in a side by side, or adjacent arrangement such that thewhite light emission from the first wavelength converter member isemitted from a separate spatial location than the IR emission from thesecond wavelength converter member. In this example, the first andsecond wavelength converter members could be excited by separate laserdiode members wherein in one embodiment the first wavelength convertermember would be excited by a first gallium and nitrogen containing laserdiodes such as violet, blue, or green laser diodes, and the secondwavelength converter member would be excited by a second gallium andnitrogen containing laser diodes such as violet, blue, or green laserdiodes. In a second embodiment of this example the first wavelengthconverter member is excited by a first gallium and nitrogen containinglaser diode such as a violet or blue laser diode, and the secondwavelength converter member is excited by a second laser diode formedfrom a different material system operating in the red or IR wavelengthregion, such as a gallium and arsenic containing material or an indiumand phosphorous containing material. In these embodiments the firstlaser diode would be excited by a first drive current and the secondlaser diode would be excited by a second drive current. Since the firstand second drive currents could be activated independently, the dualband light emitting source could provide a visible light source withonly the first driving current activated, an IR light source with onlythe second driving current activated, or could simultaneously provideboth a visible and IR light source with both the first and second drivecurrents activated. In some applications it would be desirable to onlyuse the IR illumination source for IR detection. Once an object isdetected with the IR illumination, the visible light source can beactivated to visibly illuminate the target.

FIG. 12A is a functional block diagram for a laser-based white lightsource containing a gallium and nitrogen containing violet or blue pumplaser and a wavelength converting element to generate a white lightemission, and an infrared emitting wavelength converter member togenerate an IR emission according to an embodiment of the presentinvention. Referring to FIG. 12A, a blue or violet laser device formedfrom a gallium and nitrogen containing material emitting a spectrum witha center point wavelength between 390 and 480 nm is provided. In someembodiments the gallium and nitrogen containing laser diode operates inthe 480 nm to 540 nm range. In some embodiments the laser diode iscomprised from a III-nitride material emitting in the ultraviolet regionwith a wavelength of about 270 nm to about 390 nm. The light from theviolet or blue laser device is incident on a wavelength convertingelement, which partially or fully converts the blue light into a broaderspectrum of longer wavelength light such that a white light spectrum isproduced. A laser driver is provided which powers the gallium andnitrogen containing laser device. The light from the blue laser deviceis incident on a wavelength converting element, which partially or fullyconverts the blue light into a broader spectrum of longer wavelengthlight such that a white light spectrum is produced. In some embodiments,one or more beam shaping optical elements may be provided in order toshape or focus the white light spectrum. Additionally, an IR emittingwavelength converter member with a peak emission wavelength in the 650nm to 2000 nm, or greater, range is included. A second laser device isincluded to excite the IR wavelength converter and generate the IRillumination emission. A laser driver is included to power the IRemitting laser diode. In some embodiments a beam shaper element isincluded to collect and direct the IR illumination emission. In apreferred embodiment, the IR illumination and the white lightillumination emission share at least a common beam shaping element suchthat the illumination areas of the visible light and the IR light can beapproximately super-imposed. Optionally, the one or more beam shapingoptical elements can be one selected from slow axis collimating lens,fast axis collimating lens, aspheric lens, ball lens, total internalreflector (TIR) optics, parabolic lens optics such as parabolicreflectors, refractive optics, or a combination of above. In otherembodiments, the one or more beam shaping optical elements can bedisposed prior to the laser light incident to the wavelength convertingelement.

In some embodiments the visible and/or IR emission from the light sourceare coupled into an optical waveguide such as an optical fiber, whichcould be a glass optical fiber or a plastic optical fiber. The opticalfiber of an arbitrary length, including a single mode fiber (SMF) or amulti-mode fiber (MMF), with core diameters ranging from about 1 μm to10 μm, about 10 μm to 50 μm, about 50 μm to 150 μm, about 150 μm to 500μm, about 500 μm to 1 mm, about 1 mm to 5 mm or greater than 5 mm. Theoptical fiber is aligned with a collimation optics member to receive thecollimated white light and/or IR emission.

In another embodiment of the above example, the adjacent or side by sidewavelength converter elements are excited by the same gallium andnitrogen containing laser diode with a peak wavelength in the violet orblue wavelength range. This can be accomplished in several ways. Onesuch way is to position the output laser excitation beam such that it isincident on both the first visible emitting wavelength converting memberand the second IR emitting phosphor member. This configuration could bedesigned such that the proper fraction of the beam is incident on thefirst wavelength converting member for a desired visible light emissionand a proper fraction incident on the second wavelength converter memberfor a desired IR light emission. In another such example, a beamsteering element such as a MEMS scanning mirror could be included in thesystem. The beam steering element could be programmed or manually tunedto steer the excitation laser beam to be incident on the firstwavelength converting element to generate a visible light when desiredand to steer the beam to be incident on the IR emitting phosphor whendesired. In this configuration, the dual band illumination source couldselectively illuminate in either the visible or the IR spectrum, orsimultaneously illuminate in both spectrums.

FIG. 12B is a functional block diagram for a laser-based white lightsource containing a gallium and nitrogen containing violet or blue pumplaser and a wavelength converting element to generate a white lightemission, and an infrared emitting wavelength converter member togenerate an IR emission according to an embodiment of the presentinvention. Referring to FIG. 12B, a blue or violet laser device formedfrom a gallium and nitrogen containing material emitting a spectrum witha center point wavelength between 390 and 480 nm is provided. In someembodiments the gallium and nitrogen containing laser diode operates inthe 480 nm to 540 nm range. In some embodiments the laser diode iscomprised from a III-nitride material emitting in the ultraviolet regionwith a wavelength of about 270 nm to about 390 nm. The light from theviolet or blue laser device is incident on a beam steering element suchas a MEMS scanning mirror. The beam steering element functions tooptionally steer the excitation beam to the first wavelength convertingelement to partially or fully converts the blue light into a broaderspectrum of longer wavelength light such that a white light spectrum isproduced or to a second wavelength converting element to generate an IRemission. A laser driver is provided which powers the gallium andnitrogen containing laser device. The IR emitting wavelength convertermember can have a peak emission wavelength in the 650 nm to 2000 nm, orgreater, range. In a preferred embodiment, the IR illumination and thewhite light illumination emission share at least a common beam shapingelement such that the illumination areas of the visible light and the IRlight can be approximately super-imposed. Optionally, the one or morebeam shaping optical elements can be one selected from slow axiscollimating lens, fast axis collimating lens, aspheric lens, ball lens,total internal reflector (TIR) optics, parabolic lens optics such asparabolic reflectors, refractive optics, or a combination of above. Inother embodiments, the one or more beam shaping optical elements can bedisposed prior to the laser light incident to the wavelength convertingelement. In some embodiments the visible and/or IR emission from thelight source are coupled into an optical waveguide such as an opticalfiber, which could be a glass optical fiber or a plastic optical fiber.

In another example according to this invention, the first wavelengthconverter member and the second wavelength converter member could becombined. In one combination configuration the visible emittingwavelength converter and the IR emitting wavelength converter arevertically stacked arrangement. Preferably the first wavelengthconverter member would be arranged on the same side as the primaryemission surface of the stacked wavelength converter arrangement suchthat the IR light emitted from the second wavelength converter can passthrough the first wavelength converter member without appreciableabsorption. That is, in a reflective mode configuration, the firstwavelength converter member emitting the visible light would be arrangedon top of the second wavelength converter member emitting the IR lightsuch that the visible and IR emission exiting the emission surface ofthe first wavelength converter would be collected as useful light. Thatis, the IR emission with the third peak wavelength would be emitted intothe same optical pathway as the white light emission with the first andsecond peak wavelengths.

FIG. 13A presents an example schematic diagram of a stacked phosphorconfigured for reflection mode operation wherein the IR emittingphosphor member is positioned below the visible emitting phosphor. Thestacked phosphor member in FIG. 13A is contains a reflective mirror onthe back or bottom side of the phosphor. The mirror stack can also bedesigned for a soldering attach process wherein diffusion barrier layerscan be included to prevent damage to the mirror layer when the stackedphosphor member is attached to a package or support member. The stackedphosphor member of FIG. 13A is configured with an anti-reflectivecoating and/or a roughening or patterning of the top side emissionsurface.

In another combination configuration the visible emitting wavelengthconverter and the IR emitting wavelength converter are integrated into asingle volume region to form single hybrid wavelength converter member.This can be achieved in various ways such as sintering a mixture ofwavelength converters elements such as phosphors into a single solidbody. For example, one would mix a visible light emitting phosphormember such as a YAG based phosphor with an IR emitting phosphor to forma composited phosphor or wavelength converter member. In this compositewavelength converter configuration, a common gallium and nitrogencontaining laser diode member could be configured as the excitationsource to generate both the visible light and the IR light. In thisconfiguration the activating the laser diode member with a first drivecurrent would excite both the emission of the visible light and the IRlight such that independent control of the emission of the visible lightand IR light would be difficult.

FIG. 13B presents an example schematic diagram of a composite configuredfor reflection mode operation wherein the IR emitting phosphor elementsare sintered into the same volume region as the visible emittingphosphor elements. The composite phosphor member in FIG. 13B is containsa reflective mirror on the back or bottom side of the phosphor. Themirror stack can also be designed for a soldering attach process whereindiffusion barrier layers can be included to prevent damage to the mirrorlayer when the composite phosphor member is attached to a package orsupport member. The composite phosphor member of FIG. 13B is configuredwith an anti-reflective coating and/or a roughening or patterning of thetop side emission surface.

In this composite wavelength converter configuration, a common galliumand nitrogen containing laser diode member could be configured as theexcitation source for both the first and second wavelength member. Sincethe IR and visible light emission would exit the stacked wavelengthconverter members from the same surface and within approximately thesame area, a simple optical system such as collection and collimationoptics can be used to project and direct both the visible emission andthe IR emission to the same target area. In this configurationactivating the laser diode member with a first drive current wouldexcite both the emission of the visible light and the IR light such thatindependent control of the emission of the visible light and IR lightwould be difficult. Other vertically stacked wavelength convertermembers are possible such as positioning the IR emitting secondwavelength converter member on the emission side of the stack such thatthe visible light emission from the first wavelength converter memberwould function to excite IR emission from the second wavelengthconverter member.

FIG. 14A is a functional block diagram for a laser-based white lightsource containing a gallium and nitrogen containing violet or blue pumplaser configured to excite a wavelength converting element to generate awhite light emission and a wavelength converting element to generate anIR emission according to an embodiment of the present invention.Referring to FIG. 14A, a blue or violet laser device formed from agallium and nitrogen containing material emitting a spectrum with acenter point wavelength between 390 and 480 nm is provided. In someembodiments the gallium and nitrogen containing laser diode operates inthe 480 nm to 540 nm range. In some embodiments the laser diode iscomprised from a III-nitride material emitting in the ultraviolet regionwith a wavelength of about 270 nm to about 390 nm. The light from theviolet or blue laser device is incident on a wavelength convertingelement that is comprised of both a visible emitting element and an IRemitting element, which could be configured in a stacked or compositearrangement. The visible wavelength converter element, such as aphosphor, partially or fully converts the blue light into a broaderspectrum of longer wavelength light such that a white light spectrum isproduced. Moreover, the blue light from the laser diode and/or thevisible light from the visible emitting wavelength converter memberexcites the IR emitting phosphor to generate an IR illumination. A laserdriver is provided which powers the gallium and nitrogen containinglaser device. In some embodiments, one or more beam shaping opticalelements may be provided in order to shape or focus the white lightspectrum. In a preferred embodiment, the IR illumination and the whitelight illumination emission share at least a common beam shaping elementsuch that the illumination areas of the visible light and the IR lightcan be approximately super-imposed. Optionally, the one or more beamshaping optical elements can be one selected from slow axis collimatinglens, fast axis collimating lens, aspheric lens, ball lens, totalinternal reflector (TIR) optics, parabolic lens optics such as parabolicreflectors, refractive optics, or a combination of above. In otherembodiments, the one or more beam shaping optical elements can bedisposed prior to the laser light incident to the wavelength convertingelement. In some embodiments the visible and/or IR emission from thelight source are coupled into an optical waveguide such as an opticalfiber, which could be a glass optical fiber or a plastic optical fiber.

The resulting spectrum from the embodiment described in FIG. 14Aaccording to the present invention would be comprised of a relativelynarrow band (about 0.5 to 3 nm) emission spectrum from the gallium andnitrogen containing laser diode in the UV or blue wavelength region, abroadband (about 10 to 100 nm) wavelength converter emission in thevisible spectrum with a longer peak wavelength than the UV or blue laserdiode, and a relatively broadband (about 10 to 100 nm) wavelengthconverter emission in the IR spectrum with a longer peak wavelength thanthe peak emission wavelength from the visible phosphor member. FIG. 14Bpresents an example optical spectrum according to the present invention.In this figure, the gallium and nitrogen containing laser diode emits inthe blue region at about 440 to 455 nm, the visible wavelength convertermember emits in the yellow region, and the included IR emittingwavelength converter member emits with a peak wavelength of about 850 to900 nm. Of course, there can be many other configurations of the presentinvention, including different wavelength emitting gallium and nitrogencontaining laser diodes, different wavelength emitting visible phosphormember, and different wavelength emitting IR phosphor members. Forexample, the IR emitting phosphor member could emit a peak wavelength ofbetween 700 nm and 3 μm.

In another example of the present example with the combined wavelengthconverter members the first and second wavelength converter memberscould be excited by separate laser diode members wherein in oneembodiment the first wavelength converter member would be excited by afirst gallium and nitrogen containing laser diodes such as violet orblue laser diode and the second wavelength converter member would beexcited by a second gallium and nitrogen containing laser diodes such asa green emitting or longer wavelength laser diode. In a secondembodiment of this example the first wavelength converter member isexcited by a first gallium and nitrogen containing laser diode such as aviolet or blue laser diode, and the second wavelength converter memberis excited by a second laser diode formed from a different materialsystem operating in the red or IR wavelength region, such as a galliumand arsenic containing material or an indium and phosphorous containingmaterial. The key consideration for this embodiment is to select thesecond laser diode with an operating wavelength that will not besubstantially absorbed in the first wavelength converter member, butwill be absorbed in the second wavelength converter member such thatwhen the second laser diode is activated the emission will pass throughthe first wavelength converter to excite the second wavelength converterand generate the IR emission. The result is that the first laser diodemember primarily activates the first wavelength converter member togenerate visible light and the second laser diode member primarilyactivates the second wavelength converter to generate IR light. Thebenefit to this version of the stacked wavelength converterconfiguration is that since the first laser diode would be excited by afirst drive current and the second laser diode would be excited by asecond drive current the first and second wavelength converter memberscould be activated independently such that the dual band light emittingsource could provide a visible light source with only the first drivingcurrent activated, an IR light source with only the second drivingcurrent activated, or could simultaneously provide both a visible and IRlight source with both the first and second drive currents activated. Insome applications it would be desirable to only use the IR illuminationsource for IR detection. It is to be understood that the visible lightemission from the first wavelength converter member may at leastpartially excite IR emission from the second wavelength convertermember. In this case, the source may simultaneously emit both visibleand IR emission when the visible light is activated. Thus, for dualemission of both the visible light and the IR emission, in oneembodiment according to the present invention, only the first galliumand nitrogen containing laser diode operating in the violet or blueregion may be required. However, and very importantly, when the longerwavelength laser diode is activated to excite the IR emitting wavelengthconverter member, no substantial visible light would be emitted. Thiswould enable IR illumination of a target without revealing the presenceof the illumination source. Once an object was detected, the visiblelight source could be activated.

Alternatively, the visible light emission could be excited by a firstgallium and nitrogen containing laser diode such as a violet or bluelaser diode, and the IR emission could be excited by a second laserdiode formed from a different material system operating in the red or IRwavelength region, such as a gallium and arsenic containing material oran indium and phosphorous containing material. The key consideration forthis embodiment is to select the second laser diode with an operatingwavelength that will not be substantially absorbed in the visible lightemitting element of the composite wavelength converter member, but willbe absorbed in the IR emitting element of the composite wavelengthconverter member such that when the second laser diode is activated itwill not substantially excite the visible light emission, but willexcite the IR emission. The result is that the first laser diode memberprimarily activates the first wavelength converter member to generatevisible light and the second laser diode member primarily activates thesecond wavelength converter to generate IR light. Since the IR emissionwith the third peak wavelength would be emitted from the same surfaceand spatial location as the visible emission with the first and secondpeak wavelengths, the IR emission would be easily directed into the sameoptical pathway as the white light emission with the first and secondpeak wavelengths. The IR emission and white light emission could then bedirected through the optional beam shaper configured to direct theoutput light for illuminating a target of interest. In this embodimentthe first and second driving current could be activated independentlysuch that the apparatus could provide a visible light source with onlythe first driving current activated, an IR light source with the seconddriving current activated, or could simultaneously provide both avisible and IR light source. In some applications it would be desirableto only use the IR illumination source for IR detection. Once an objectis detected with the IR illumination, the visible light source can beactivated to visibly illuminate the target.

The benefit to this version of the stacked wavelength converterconfiguration is that since the first laser diode would be excited by afirst drive current and the second laser diode would be excited by asecond drive current the first and second wavelength converter memberscould be activated independently such that the dual band light emittingsource could provide a visible light source with only the first drivingcurrent activated, an IR light source with only the second drivingcurrent activated, or could simultaneously provide both a visible and IRlight source with both the first and second drive currents activated. Itis to be understood that the visible light emission from the firstwavelength converter member may at least partially excite IR emissionfrom the second wavelength converter member. In this case, the sourcemay simultaneously emit both visible and IR emission when the visiblelight is activated. Thus, for dual emission of both the visible lightand the IR emission, in one embodiment according to the presentinvention only the first gallium and nitrogen containing laser diodeoperating in the violet or blue region may be required. However, andvery importantly, when the longer wavelength laser diode is activated toexcite the IR emitting wavelength converter member, no substantialvisible light would be emitted. This would enable IR illumination of atarget without revealing the presence of the illumination source. Insome applications it would be desirable to only use the IR illuminationsource for IR detection. Once an object was detected, the visible lightsource could be activated.

FIG. 15A is a functional block diagram for a laser-based white lightsource containing a gallium and nitrogen containing violet or blue pumplaser configured to excite a wavelength converting element to generate awhite light emission, and an IR emitting laser diode configured to pumpan IR wavelength converting element to generate an IR emission accordingto an embodiment of the present invention. Referring to FIG. 15A, a blueor violet laser device formed from a gallium and nitrogen containingmaterial emitting a spectrum with a center point wavelength between 390and 480 nm is provided. In some embodiments the gallium and nitrogencontaining laser diode operates in the 480 nm to 540 nm range. In someembodiments the laser diode is comprised from a III-nitride materialemitting in the ultraviolet region with a wavelength of about 270 nm toabout 390 nm. The light from the violet or blue laser device is incidenton a wavelength converting element that is comprised of both a visibleemitting element and an IR emitting element, which could be configuredin a stacked or composite arrangement. The visible wavelength converterelement, such as a phosphor, partially or fully converts the blue lightinto a broader spectrum of longer wavelength light such that a whitelight spectrum is produced. In some embodiments the blue light from thelaser diode and/or the visible light from the visible emittingwavelength converter member could excite the IR emitting phosphor togenerate an IR illumination. A laser driver is provided which powers thegallium and nitrogen containing laser device. A second laser diode isincluded. The second laser diode operates with a peak wavelength that islonger than the visible emission from the first wavelength convertermember, but shorter than the peak wavelength of the IR emittingwavelength converter member. A second laser driver is configured todrive the second laser diode member. The output electromagnetic emissionfrom the second laser diode member is configured to preferentiallyexcite the IR emitting phosphor member without substantially excitingthe visible phosphor member. In some embodiments, one or more beamshaping optical elements may be provided in order to shape or focus thewhite light and the IR emission spectrums. In a preferred embodiment,the IR illumination and the white light illumination emission share atleast a common beam shaping element such that the illumination areas ofthe visible light and the IR light can be approximately super-imposed.Optionally, the one or more beam shaping optical elements can be oneselected from slow axis collimating lens, fast axis collimating lens,aspheric lens, ball lens, total internal reflector (TIR) optics,parabolic lens optics such as parabolic reflectors, refractive optics,or a combination of above. In other embodiments, the one or more beamshaping optical elements can be disposed prior to the laser lightincident to the wavelength converting element.

In some embodiments the visible and/or IR emission from the light sourceare coupled into an optical waveguide such as an optical fiber, whichcould be a glass optical fiber or a plastic optical fiber. The opticalfiber of an arbitrary length, including a single mode fiber (SMF) or amulti-mode fiber (MMF), with core diameters ranging from about 1 μm to10 μm, about 10 μm to 50 μm, about 50 μm to 150 μm, about 150 μm to 500μm, about 500 μm to 1 mm, about 1 mm to 5 mm or greater than 5 mm. Theoptical fiber is aligned with a collimation optics member to receive thecollimated white light and/or IR emission.

The resulting spectrum from the embodiment described in FIG. 15Aaccording to the present invention would be comprised of a relativelynarrow band (about 0.5 to 3 nm) emission spectrum from the gallium andnitrogen containing laser diode in the UV or blue wavelength region, abroadband (about 10 to 100 nm) wavelength converter emission in thevisible spectrum with a longer peak wavelength than the UV or blue laserdiode, a relatively narrow band (about 1 to 10 nm) emission from thesecond laser diode with a peak wavelength longer than the peakwavelength of the visible emitting phosphor, and a relatively broadband(about 10 to 100 nm) wavelength converter emission in the IR spectrumwith a longer peak wavelength than the peak emission wavelength from thesecond laser diode. FIG. 15B presents an example optical spectrumaccording to the present invention. In this figure, the gallium andnitrogen containing laser diode emits in the blue region at about 440 to455 nm, the visible wavelength converter member emits in the yellowregion, the second laser diode member emits with a peak wavelength of900 nm, and the included IR emitting wavelength converter member emitswith a peak wavelength of about 1100 nm. Of course, there can be manyother configurations of the present invention, including differentwavelength emitting gallium and nitrogen containing laser diodes,different wavelength emitting visible phosphor member, and differentwavelength emitting IR phosphor members. For example, the IR emittingphosphor member could emit a peak wavelength of between 700 nm and 3 μm.

In preferred embodiments according to the present invention, thewavelength converter element is comprised of one or more phosphormembers. Such phosphor members can be implemented in solid body formsuch as single crystal phosphor element, a ceramic element, or aphosphor in a glass, or could be in a powder form wherein the powder isbound by a binder material. There is a wide range of phosphorchemistries to select from to ensure the proper emission and performanceproperties. Moreover, such phosphor members can be operated in severalarchitectural arrangements such as a reflective mode, a transmissivemode, a hybrid mode, or any other mode.

In some embodiments, a deep UV laser is included wherein the deep UVlaser is configured to excite a UV phosphor element to emit a UV light.In such a configuration, the UV emission could be deployed as a UVillumination source for UV imaging. In a further example of the presentembodiment, deep UV laser could also be configured to excite a visibleemitting wavelength converter member, and/or an IR emitting wavelengthconverter member.

In some embodiments, the light engine is provided with a plurality ofblue or violet pump lasers which are incident on a first surface of thewavelength converting element. The plurality of blue or violet pumplasers is configured such that each pump laser illuminates a differentregion of the first surface of the wavelength converting element. In aspecific embodiment, the regions illuminated by the pump lasers are notoverlapping. In a specific embodiment, the regions illuminated by thepump lasers are partially overlapping. In a specific embodiment, asubset of pump lasers illuminate fully overlapping regions of the firstsurface of the wavelength converting element while one or more otherpump lasers are configured to illuminate either a non-overlapping orpartially overlapping region of the first surface of the wavelengthconverting element. Such a configuration is advantageous because bydriving the pump lasers independently of one another the size and shapeof the resulting light source can by dynamically modified such that theresulting spot of white light once projected through appropriate opticalelements can by dynamically configured to have different sizes andshapes without the need for a moving mechanism.

In an alternative embodiment, the laser or SLED pump light sources andthe wavelength converting element are contained in a sealed packageprovided with an aperture to allow the white light spectrum to beemitted from the package. In specific embodiments, the aperture iscovered or sealed by a transparent material, though in some embodimentsthe aperture may be unsealed. In an example, the package is a TOcanister with a window that transmits all or some of the pump anddown-converted light. In an example, the package is a TO canister with awindow that transmits all or some of the pump and down-converted light.

FIG. 16A is a schematic diagram of a laser based white light sourceconfigured with an IR illumination capability operating in transmissionmode and housed in a TO canister style package according to anembodiment of the present invention. Referring to FIG. 16A, the TOcanister package includes a base member 1001, a shaped pedestal 1005 andpins 1002. The base member 1001 can be comprised of a metal such ascopper, copper tungsten, aluminum, or steel, or other. The pins 1002 areeither grounded to the base or are electrically insulated from it andprovide a means of electrically accessing the laser device. The pedestalmember 1005 is configured to transmit heat from the pedestal to the basemember 1001 where the heat is subsequently passed to a heat sink. A capmember 1006 is provided with a window 1007 hermetically sealed. The capmember 1006 itself also is hermetically sealed to the base member 1001to enclose the laser based white light source in the TO canisterpackage.

A laser device 1003 and a wavelength converting member 104 are mountedon the pedestal 1005. In some embodiments intermediate submount membersare included between the laser diode and the pedestal and/or between thewavelength converter member and the pedestal. The mounting to thepedestal can be accomplished using a soldering or gluing technique suchas using AuSn solders, SAC solders such as SAC305, lead containingsolder, or indium, but can be others. In an alternative embodimentsintered Ag pastes or films can be used for the attach process at theinterface. Sintered Ag attach material can be dispensed or depositedusing standard processing equipment and cycle temperatures with theadded benefit of higher thermal conductivity and improved electricalconductivity. For example, AuSn has a thermal conductivity of about 50W/m-K and electrical conductivity of about 16μΩcm whereas pressurelesssintered Ag can have a thermal conductivity of about 125 W/m-K andelectrical conductivity of about 4μΩcm, or pressured sintered Ag canhave a thermal conductivity of about 250 W/m-K and electricalconductivity of about 2.5 μΩcm. Due to the extreme change in melttemperature from paste to sintered form, for example, 260° C.-900° C.,processes can avoid thermal load restrictions on downstream processes,allowing completed devices to have very good and consistent bondsthroughout. Electrical connections from the p-electrode and n-electrodeof the laser diode are made using wire bonds 1008 which connect to thepins 1002. The pins are then electrically coupled to a power source toelectrify the white light source and generate white light emission. Inthis configuration the white light source is not capped or sealed suchthat is exposed to the open environment.

The laser light emitted from the laser device 1003 shines through thewavelength converting element 1004 and is either fully or partiallyconverted to longer wavelength light. The down-converted light andremaining laser light is then emitted from the wavelength convertingelement 1004. The laser activated phosphor member white light sourceconfigured in a can type package as shown in FIG. 16A includes anadditional cap member 1006 to form a sealed structure around the whitelight source on the base member 1001. The cap member 1006 can besoldered, brazed, welded, or glue to the base. The cap member 1006 has atransparent window 1007 configured to allow the emitted white light topass to the outside environment where it can be harnessed inapplication. The sealing type can be an environmental seal or a hermeticseal, and in an example the sealed package is backfilled with a nitrogengas or a combination of a nitrogen gas and an oxygen gas. Optionally,the window 1007 and cap member 1006 are joined using epoxy, glue, metalsolder, glass frit sealing and friction welding among other bondingtechniques appropriate for the window material. Optionally, the capmember 1006 is either crimped onto the header of the base member 1001 orsealed in place using epoxy, glue, metal solder, glass frit sealing andfriction welding among other bonding techniques appropriate for the capmaterial such that a hermetic seal is formed.

The laser devices are configured such that they illuminate thewavelength converting element 1004 and any non-converted pump light istransmitted through the wavelength converting element 1004 and exits thecanister through the window 1007 of the cap member 1006. Down-convertedlight emitted by the wavelength converting element is similarly emittedfrom the TO canister through the window 1007.

In some configurations of the present invention, TO can type packagescan be used to package the laser-based IR illumination source. FIG. 16Bpresents a side view schematic diagram of a laser-based IR illuminationsource capable for operating in transmission mode and housed in a TOcanister style package with an IR emitting wavelength converter memberconfigured with the transparent window of the cap according to anembodiment of the present invention. Referring to FIG. 16B, the TO cancomprises a base member configured for transporting the heat generatedin the package to a heat-sink member. Electrical feedthrough pins areconfigured to supply current to the anode and cathode of the laser diodefrom an external power source. A laser diode is mounted on a pedestalmember within the TO can package, and the package is sealed with a capmember. The cap member comprises a transparent window member configuredto allow visible and IR light to pass through the window to the outsideenvironment. The transparent window member comprises an IR emittingwavelength converting member, configured to emit IR illumination whenthe laser diode excitation beam is incident on the window member. Insome embodiments, the wavelength converter member serves as the windowmember.

In some configurations of the present invention, TO can type packagescan be used to package the laser based white light source configuredwith an IR illumination source. FIG. 16C presents a side view schematicdiagram of a laser based white light source with an IR illuminationcapable of operating in a transmission mode and housed in a TO canisterstyle package with a visible and IR emitting wavelength converter memberconfigured with the transparent window of the cap according to anembodiment of the present invention. Referring to FIG. 16C, the TO cancomprises a base member configured for transporting the heat generatedin the package to a heat-sink member. Electrical feedthrough pins areconfigured to supply current to the anode and cathode of the laser diodefrom an external power source. A laser diode is mounted on a pedestalmember within the TO can package, and the package is sealed with a capmember. The cap member comprises a transparent window member configuredto allow visible and IR light to pass through the window to the outsideenvironment. The transparent window member comprises a visible and IRemitting wavelength converting member, configured to emit visible lightsuch as white light and IR illumination when the laser diode excitationbeam is incident on the window member. In some embodiments, thewavelength converter member serves as the window member.

FIG. 16D is a side view schematic diagram of an IR and visible lightemitting based wavelength converter member configured with thetransparent window of the cap according to an embodiment of the presentinvention. In this embodiment the wavelength converter member iscomprised of a stacked IR emitting wavelength converter and visiblelight emitting wavelength converter. According to this example, the UVor blue laser diode excitation illumination is incident on the visiblelight emitting wavelength converter first, wherein the excitation lightand the emitted visible light excites the IR emitting phosphor. In otherembodiments the UV of blue laser diode excitation beam could be incidenton the IR wavelength converter member first such that the light thatpenetrates the IR illumination phosphor would enter into the visibleemitting wavelength converter member to excite a visible light. In otherconfigurations, composite wavelength converter structures are configuredto create the visible light and IR light.

In an embodiment, the laser based white light source configured with anIR illumination source is packaged in a TO canister with a window thattransmits all or some of the pump and down-converted light and thewavelength converting element is illuminated in a reflection mode. FIG.16E is a schematic diagram of a laser based white light source operatingin reflection mode and housed in a TO canister style package accordingto another embodiment of the present invention. The canister baseconsists of a header 1106, wedge shaped member 1102 and electricallyisolated pins that pass-through the header. The laser devices 1101 andthe wavelength converting element 1105 are mounted to the wedge-shapedmember 1102 and pedestal, respectively, using a thermally conductivebonding media such as silver epoxy or with a solder material, preferablychosen from one or more of AuSn, AgCuSn, PbSn, or In. The package issealed with a cap 1103 which is fitted with a transparent window 1104.The window 1104 and cap 1103 are joined using epoxy, glue, metal solder,glass frit sealing and friction welding among other bonding techniquesappropriate for the window material. The cap 1103 is either crimped ontothe header 1106 or sealed in place using epoxy, glue, metal solder,glass frit sealing and friction welding among other bonding techniquesappropriate for the cap material such that a hermetic seal is formed.The laser devices are configured such that they illuminate thewavelength converting element 1105 and any non-converted pump light isreflected or scattered from the wavelength converting element 1105 andexits the canister through the cap window 1104. Down-converted lightemitted by the wavelength converting element 1105 is similarly emittedfrom the canister through the window 1104.

In another embodiment, a reflective mode integrated white light sourceis configured in a flat type package with a lens member to create acollimated white beam. The flat type package has a base or housingmember with a collimated white light source mounted to the base andconfigured to create a collimated white beam to exit a window configuredin the side of the base or housing member. The mounting to the base orhousing can be accomplished using a soldering or gluing technique suchas using AuSn solders, SAC solders such as SAC305, lead containingsolder, or indium, but can be others. In an alternative embodimentsintered Ag pastes or films can be used for the attach process at theinterface. Sintered Ag attach material can be dispensed or depositedusing standard processing equipment and cycle temperatures with theadded benefit of higher thermal conductivity and improved electricalconductivity. For example, AuSn has a thermal conductivity of about 50W/m-K and electrical conductivity of about 16μΩcm whereas pressurelesssintered Ag can have a thermal conductivity of about 125 W/m-K andelectrical conductivity of about 4μΩcm, or pressured sintered Ag canhave a thermal conductivity of about 250 W/m-K and electricalconductivity of about 2.5 μΩcm. Due to the extreme change in melttemperature from paste to sintered form, (260° C.-900° C.), processescan avoid thermal load restrictions on downstream processes, allowingcompleted devices to have very good and consistent bonds throughout.Electrical connections to the white light source can be made with wirebonds to the feedthroughs that are electrically coupled to externalpins. In this example, the collimated reflective mode white light sourceincludes the laser diode, the phosphor wavelength converter configuredto accept the laser beam, and a collimating lens such as an asphericlens configured in front of the phosphor to collect the emitted whitelight and form a collimated beam. The collimated beam is directed towardthe window wherein the window region is formed from a transparentmaterial. The transparent material can be a glass, quartz, sapphire,silicon carbide, diamond, plastic, or any suitable transparent material.The external pins are electrically coupled to a power source toelectrify the white light source and generate white light emission.

In one embodiment according to the present invention, a transmissivemode integrated white light source is configured in a flat type packagewith a lens member to create a collimated white beam. In one example ofthis embodiment, the white light emission is collimated and projectedtoward a window configured on the flat-type package wherein thecollimated white beam of light exits the transparent window and isguided by free space optical path or a fiber coupled optical path to thetarget subject or area.

There are several configurations that enable a remote pumping ofphosphor material using one or more laser diode excitation sources. Inan embodiment one or more laser diodes are remotely coupled to one ormore phosphor members with a free-space optics configuration. That is,at least part of the optical path from the emission of the laser diodeto the phosphor member is comprised of a free-space optics setup. Insuch a free-space optics configuration the optical beam from the laserdiode may be shaped using optical elements such as collimating lensincluding a fast axis collimator, slow axis collimator, aspheric lens,ball lens, or other elements such as glass rods. In other embodiments ofa free-space optical pumping the beam may not be shaped and simplydirectly coupled to the phosphor. In another embodiment a waveguideelement is used to couple the optical excitation power from the one ormore laser diodes to the phosphor member. The waveguide element includesone or more materials selected from Si, SiN, GaN, GaInP, Oxides, orothers.

In another embodiment, an optical fiber is used as the waveguide elementwherein on one end of the fiber the electromagnetic radiation from theone or more laser diodes is in-coupled to enter the fiber and on theother end of the fiber the electromagnetic radiation is out-coupled toexit the fiber wherein it is then incident on the phosphor member. Theoptical fiber could be comprised of a glass material such as silica, apolymer material, or other, and could have a length ranging from 100 μmto about 100 m or greater.

In alternative examples, the waveguide element could consist of glassrods, optical elements, specialized waveguide architectures such assilicon photonics devices.

In one embodiment the laser diode members are comprised of laser bars,wherein the laser bar includes a number of emitters with cavity membersformed by ridge structures, the cavity members are electrically coupledto each other by the electrode. The laser diodes, each having anelectrical contact through its cavity member, share a common n-sideelectrode. Depending on the application, the n-side electrode can beelectrically coupled to the cavity members in different configurations.In a preferred embodiment, the common n-side electrode is electricallycoupled to the bottom side of the substrate. In certain embodiments,n-contact is on the top of the substrate, and the connection is formedby etching deep down into the substrate from the top and then depositingmetal contacts. For example, laser diodes are electrically coupled toone another in a parallel configuration. In this configuration, whencurrent is applied to the electrodes, all laser cavities can be pumpedrelatively equally. Further, since the ridge widths will be relativelynarrow in the 1.0 to 5.0 μm range, the center of the cavity member willbe in close vicinity to the edges of the ridge (e.g., via) such thatcurrent crowding or non-uniform injection will be mitigated. In anadditional embodiment including laser bars, the individual laser diodecomprising the laser bar are electrically coupled in series. In yet anadditional embodiment including laser bars, the individual laser diodecomprising the laser bar are individually addressable. For example,electrodes can be individually coupled to the emitters so that it ispossible to selectively turning a emitter on and off.

It is to be appreciated that the laser device with multiple cavitymembers has an effective ridge width of n×w, which could easily approachthe width of conventional high-power lasers having a width in the 10 to50 μm range. Typical lengths of this multi-stripe laser could range from400 μm to 2000 μm, but could be as much as 3000 μm. These laser deviceshave a wide range of applications. For example, the laser device can becoupled to a power source and operate at a power level of 0.5 to 10 W.In certain applications, the power source is specifically configured tooperate at a power level of greater than 10 W. The operating voltage ofthe laser device can be less than 5 V, 5.5 V, 6 V, 6.5 V, 7 V, and othervoltages. In various embodiments, the wall plug efficiency (e.g., totalelectrical-to-optical power efficiency) can be 15% or greater, 20% orgreater, 25% or greater, 30% or greater, 35% or greater.

In some embodiments of the present invention, multi-chip laser diodemodules are utilized. For example, an enclosed free-space beam combinedmulti-chip laser module with an extended delivery fiber plus phosphorconverter could be included according to the present invention. Theenclosed free space multi-chip laser module produces a laser light beamin violet or blue light spectrum, with optional IR emitting laser diodesincluded. The multiple laser chips in the package provide substantiallyhigh intensity for the light source that is desired for many newapplications. Additionally, an extended optical fiber with one end iscoupled with the light guide output for further guiding the laser lightbeam to a desired distance for certain applications up to 100 m orgreater. Optionally, the optical fiber can be also replaced by multiplewaveguides built in a planar structure for integrating with siliconphotonics devices. At the other end of the optical fiber, a phosphormaterial-based wavelength converter may be disposed to receive the laserlight, where the violet or blue color laser light is converted to whitecolor light and emitted out through an aperture or collimation device.As a result, a white light source with small size, remote pump, andflexible setup is provided.

In another example, the package is a custom package made from one ormore of plastic, metal, ceramics and composites.

In another embodiment, the laser devices are co-packaged on a commonsubstrate along with the wavelength converting element. A shaped membermay be provided separating either the laser devices or the wavelengthconverting element from the common substrate such that the pump light isincident on the wavelength converting element at some angle which is notparallel to the surface normal of the wavelength covering member.Transmission mode configurations are possible, where the laser light isincident on a side of the wavelength converting element not facing thepackage aperture. The package can also contain other optical, mechanicaland electrical elements.

In an embodiment, the common substrate is a solid material with thermalconductivity greater than 100 W/m-K. In an example, the common substrateis preferably a solid material with thermal conductivity greater than200 W/m-K. In an example, the common substrate is preferably a solidmaterial with thermal conductivity greater than 400 W/m-K. In anexample, the common substrate is preferably a solid material withelectrical insulator with electrical resistivity greater than 1×10⁶ Ωcm.In an example, the common substrate is preferably a solid material withthin film material providing electrical 1×10⁶ Ωcm. In an example, thecommon substrate selected from one or more of Al₂O₃, AlN, SiC, BeO anddiamond. In an example, the common substrate is preferably comprised ofcrystalline SiC. In an example, the common substrate is preferablycomprised of crystalline SiC with a thin film of Si₃N₄ deposited ontothe top surface. In an example, the common substrate contains metaltraces providing electrically conductive connections between the one ormore laser diodes. In an example, the common substrate contains metaltraces providing thermally conductive connections between the one ormore laser diodes and the common substrate.

In an embodiment, the common substrate is a composite structurecomprised by a plurality or layers or regions of differing compositionor electrical conductivity. In an example, the common substrate is ametal-core printed circuit board comprised by a core layer of aluminumor copper surrounded by layers of insulating plastic. Through vias,solder masks and solder pads may be provided. In an example, the commonsubstrate is a ceramic substrate comprised by a ceramic core plate cladin patterned metallic pads for bonding and electrical contact. Theceramic substrate may contain metal filled vias for providing electricalcommunication between both faces of the ceramic plate. In an example,the common substrate consists of a metal core or slug surrounded by aninsulating material such as plastic or ceramic. The surroundinginsulating material may contain through vias for electricalcommunication between the front and back faces of the substrate. Theinsulating material may also have metallic or otherwise conducting padspatterned on it for wire-bonding.

In an embodiment, the one or more laser diodes are attached to thecommon substrate with a solder material. In an example, the one or morelaser diodes are attached to the metal traces on the common substratewith a solder material, preferably chosen from one or more of AuSn,AgCuSn, PbSn, or In.

In an embodiment, the wavelength conversion material is attached to thecommon substrate with a solder material. In an example, the wavelengthconversion material is attached to the metal traces on the commonsubstrate with a solder material, preferably chosen from one or more ofAuSn, AgCuSn, PbSn, or In.

In an example, the wavelength conversion element contains an opticallyreflective material interposed between the wavelength conversion elementand the thermally conductive connection to the common substrate.

In an embodiment, the optically reflective material interposed betweenthe wavelength conversion element and the thermally conductiveconnection to the common substrate has a reflectivity value of greaterthan 50%. In an embodiment the optically reflective material interposedbetween the wavelength conversion element and the thermally conductiveconnection to the common substrate has a reflectivity value of greaterthan 80%. In an example, the optically reflective material interposedbetween the wavelength conversion element and the thermally conductiveconnection to the common substrate has a reflectivity value of greaterthan 90%. In an example, optical beam shaping elements are placedbetween the laser diodes and the wavelength conversion element.

In an embodiment, the wavelength conversion element contains geometricalfeatures aligned to each of the one or more laser diodes. In an example,the wavelength conversion element further contains an opticallyreflective material on the predominate portion of the edgesperpendicular to the common substrate and one or more laser diodes, andwhere the geometrical features aligned to each of the laser diodes doesnot contain an optically reflective material. In an example, the commonsubstrate is optically transparent. In an example, the wavelengthconversion element is partially attached to the transparent commonsubstrate. In an example, the wavelength converted light is directedthrough the common substrate. In an example, the wavelength convertercontains an optically reflective material on at least the top surface.In an example, the one or more laser diodes and the wavelengthconversion element are contained within a sealing element to reduce theexposure to the ambient environment. In an example, the one or morelaser diodes and the wavelength conversion element are contained withina sealing element to reduce the exposure to the ambient environment.

FIG. 17A is a schematic diagram illustrating an off-axis reflective modeembodiment of an integrated laser-phosphor white light source accordingto the present invention. In this embodiment the gallium and nitrogencontaining lift-off and transfer technique is deployed to fabricate avery small and compact submount member with the laser diode chip formedfrom transferred epitaxy layers. Further, in this example the phosphoris tilted with respect to the fast axis of the laser beam at an angleω₁. The laser based white light device is comprised of a support member1401 that serves as the support member for the laser diode CoS 1402formed in transferred gallium and nitrogen containing epitaxial layers1403. The phosphor material 1406 is mounted on a support member 1408wherein the support members 1401 and 1408 would be attached to a commonsupport member such as a surface in a package member such as a surfacemount package. The laser diode or CoS is configured with electrodes 1404and 1405 that may be formed with deposited metal layers and combinationof metal layers including, but not limited to Au, Pd, Pt, Ni, Al, Agtitanium, or others such as transparent conductive oxides such as indiumtin oxide. The laser beam output excites the phosphor material 1406positioned in front of the output laser facet. The electrodes 1404 and1405 are configured for an electrical connection to an external powersource such as a laser driver, a current source, or a voltage source.Wirebonds can be formed on the electrodes to couple electrical power tothe laser diode device to generate a laser beam 1407 output from thelaser diode and incident on the phosphor 1406. Of course this is merelyan example of a configuration and there could be many variants on thisembodiment including but not limited to different shape phosphors,different geometrical designs of the submount, support members,different orientations of the laser output beam with respect to thephosphor, different electrode and electrical designs, and others.

FIG. 17B is a schematic diagram illustrating an off-axis reflective modephosphor with two laser diode devices embodiment of an integratedlaser-phosphor white light source according to the present invention. Inthis embodiment the gallium and nitrogen containing lift-off andtransfer technique is deployed to fabricate a very small and compactsubmount member with the laser diode chip formed from transferredepitaxy layers. Further, in this example the phosphor is tilted withrespect to the fast axis of the laser beam at an angle ω₁. The laserbased white light sources is comprised of two or more laser diodesincluding support members 1401 that serves as the support member for thetwo laser diodes 1402 formed in transferred gallium and nitrogencontaining epitaxial layers 1403. The phosphor material 1406 is mountedon a support member 408 wherein the support members 1401 and 1408 wouldbe attached to a common support member such as a surface in a packagemember such as a surface mount package. The laser diodes or CoS devicesare configured with electrodes 1404 and 1405 that may be formed withdeposited metal layers and combination of metal layers including, butnot limited to Au, Pd, Pt, Ni, Al, Ag titanium, or others such astransparent conductive oxides such as indium tin oxide. The multiplelaser beams 1407 excite the phosphor material 1406 positioned in frontof the output laser facet.

Referring to FIG. 17B the laser diode excitation beams 1407 are rotatedwith respect to each other such that the fast axis of the first beam isaligned with the slow axis of the second beam to form a more circularexcitation spot. The electrodes 1404 and 1405 are configured for anelectrical connection to an external power source such as a laserdriver, a current source, or a voltage source. Wirebonds can be formedon the electrodes to couple electrical power to the laser diode deviceto generate the multiple laser beams 1407 incident on the phosphor 1406.Of course this is merely an example of a configuration and there couldbe many variants on this embodiment including but not limited to morethan two laser diodes such as three of four laser diodes, differentshape phosphors, different geometrical designs of the submount, supportmembers, different orientations of the laser output beam with respect tothe phosphor, wiring the laser diodes in series or parallel, differentelectrode and electrical designs including individually addressablelasers, and others.

FIG. 18A is a schematic diagram of an exemplary laser based white lightsource operating in reflection mode and housed in a surface mountpackage according to an embodiment of the present invention. Referringto FIG. 18A, a reflective mode white light source is configured in asurface mount device (SMD) type package. The SMD package has a commonsupport base member 1601. The reflective mode phosphor member 1602 isattached to the base member 1601. Optionally, an intermediate submountmember may be included between the phosphor member 1602 and the basemember 1601. The laser diode 1603 is mounted on an angled support member1604, wherein the angled support member 1604 is attached to the basemember 1601. The base member 1601 is configured to conduct heat awayfrom the white light source and to a heat sink. The base member 1601 iscomprised of a thermally conductive material such as copper, coppertungsten, aluminum, SiC, steel, diamond, composite diamond, AlN,sapphire, or other metals, ceramics, or semiconductors.

The mounting to the base member 1601 can be accomplished using asoldering or gluing technique such as using AuSn solders, SAC solderssuch as SAC305, lead containing solder, or indium, but can be others.Alternatively, sintered Ag pastes or films can be used for the attachprocess at the interface. Sintered Ag attach material can be dispensedor deposited using standard processing equipment and cycle temperatureswith the added benefit of higher thermal conductivity and improvedelectrical conductivity. For example, AuSn has a thermal conductivity ofabout 50 W/m-K and electrical conductivity of about 16 μΩcm whereaspressureless sintered Ag can have a thermal conductivity of about 125W/m-K and electrical conductivity of about 4 μΩcm, or pressured sinteredAg can have a thermal conductivity of about 250 W/m-K and electricalconductivity of about 2.5 μΩcm. Due to the extreme change in melttemperature from paste to sintered form, 260° C.-900° C., processes canavoid thermal load restrictions on downstream processes, allowingcompleted devices to have very good and consistent bonds throughout. Themounting joint could also be formed from thermally conductive glues,thermal epoxies such as silver epoxy, and other materials.

Electrical connections from the electrodes of the laser diode are madeto using wirebonds 1605 to electrode members 1606. Wirebonds 1607 and1608 are formed to internal feedthroughs 1609 and 1610. The feedthroughsare electrically coupled to external leads. The external leads can beelectrically coupled to a power source to electrify the white lightsource and generate white light emission.

The top surface of the base member 1601 may be comprised of, coatedwith, or filled with a reflective layer to prevent or mitigate anylosses relating from downward directed or reflected light. Moreover, allsurfaces within the package including the laser diode and submountmember may be enhanced for increased reflectivity to help improve theuseful white light output.

In this configuration the white light source is not capped or sealedsuch that is exposed to the open environment. In some examples of thisembodiment of the integrated white light source apparatus, anelectrostatic discharge (ESD) protection element such as a transientvoltage suppression (TVS) element is included. Of course, FIG. 18A ismerely an example and is intended to illustrate one possible simpleconfiguration of a surface mount packaged white light source.Specifically, since surface mount type packages are widely popular forLEDs and other devices and are available off the shelf, they could beone option for a low cost and highly adaptable solution.

FIG. 18B is an alternative example of a packaged white light sourceincluding 2 laser diode chips according to the present invention. Inthis example, a reflective mode white light source is configured also ina SMD type package. The SMD package has a base member 1601 with thereflective mode phosphor member 1602 mounted on a support member or on abase member. A first laser diode device 1613 may be mounted on a firstsupport member 1614 or a base member 1601. A second laser diode device1615 may be mounted on a second support member 1616 or a base member1601. The support members and base member are configured to conduct heataway from the phosphor member 1602 and laser diode devices 1613 and1615.

The external leads can be electrically coupled to a power source toelectrify the laser diode sources to emit a first laser beam 1618 fromthe first laser diode device 1613 and a second laser beam 1619 from asecond laser diode device 1615. The laser beams are incident on thephosphor member 1602 to create an excitation spot and a white lightemission. The laser beams are preferably overlapped on the phosphormember 1602 to create an optimized geometry and/or size excitation spot.For example, the laser beams from the first and second laser diodes arerotated by 90 degrees with respect to each other such that the slow axisof the first laser beam 1618 is aligned with the fast axis of the secondlaser beam 1619.

The top surface of the base member 1601 may be comprised of, coatedwith, or filled with a reflective layer to prevent or mitigate anylosses relating from downward directed or reflected light. Moreover, allsurfaces within the package including the laser diode member andsubmount member may be enhanced for increased reflectivity to helpimprove the useful white light output. In this configuration the whitelight source is not capped or sealed such that is exposed to the openenvironment. In some examples of this embodiment of the integrated whitelight source apparatus, an ESD protection element such as a TVS elementis included. Of course, FIG. 18B is merely an example and is intended toillustrate one possible simple configuration of a surface mount packagedwhite light source. Specifically, since surface mount type packages arewidely popular for LEDs and other devices and are available off theshelf, they could be one option for a low cost and highly adaptablesolution.

FIG. 18C is an alternative example of a packaged white light sourceaccording to the present invention. In this example, a reflective modewhite light source is configured also in a SMD type package. The SMDpackage has a base member 1601 serving as a common support member for aside-pumped phosphor member 1622 mounted on a submount or support member1623 and a laser diode device 1624 mounted on a submount or supportmember 1625. In some embodiments, the laser diode 1624 and or thephosphor member 1622 may be mounted directly to the base member 1601 ofthe package. The support members and base member 1601 are configured toconduct heat away from the phosphor member 1622 and laser diode device1624. The base member 1601 is substantially the same type as that inFIG. 18A and FIG. 18B in the SMD type package.

Electrical connections from the p-electrode and n-electrode can beelectrically coupled to 1626 and 1627 electrodes on a submount member1625 which would then be coupled to internal feedthroughs in thepackage. The feedthroughs are electrically coupled to external leads.The external leads can be electrically coupled to a power supply sourceto electrify the laser diode and generate a laser beam incident on theside of the phosphor member 1622. The phosphor member 1622 maypreferably be configured for primary white light emission 1628 from thetop surface of the phosphor member 1622. The top surface of the basemember 1601 may be comprised of, coated with, or filled with areflective layer to prevent or mitigate any losses relating fromdownward directed or reflected light. Moreover, all surfaces within thepackage including the laser diode member and submount member may beenhanced for increased reflectivity to help improve the useful whitelight output. In this configuration the white light source is not cappedor sealed such that is exposed to the open environment. In some examplesof this embodiment of the integrated white light source apparatus, anESD protection element such as a TVS element is included. Of course, theexample in FIG. 18C is merely an example and is intended to illustrateone possible simple configuration of a surface mount packaged whitelight source. Specifically, since surface mount type packages are widelypopular for LEDs and other devices and are available off the shelf, theycould be one option for a low cost and highly adaptable solution.

The white light sources shown in FIGS. 18A, 18B, and 18C can be enclosedin a number of ways to form a light engine. Optionally, the light engineis encapsulated in a molded epoxy or plastic cover (not shown). Themolded cover may have a flat top or can be molded to have a curved orspherical surface to aid in light extraction. It is possible for thecover to be pre-molded and glued in place, or to be molded in place fromliquid or gel precursors. Because a polymer cover or moldedencapsulating material may absorb laser light or down converted lightfrom the wavelength converting element there is a large risk that theencapsulating material will age due to heating and light absorption.When such a material ages, it tends to become more optically absorbing,leading to a runaway process that inevitably leads to device failure. Ina laser-based device, where the laser devices emit light with a veryhigh brightness and optical flux, this aging effect is expected to bequite severe. It is preferred, then, for a polymer cover to be absentfrom the region near the emitting facets of the lasers as well as fromthe path of the laser beams between the laser devices and the wavelengthconverting element. Optionally, the molded cover does not contact thelaser device nor the wavelength converting element nor does it intersectthe laser light beams prior to their intersecting the wavelengthconverting element. Optionally, the molded cover overlays and is incontact with a part or majority of the laser devices and the wavelengthconverting element, but does not cover the emitting facet of the lasersnor the surface of the wavelength converting element, nor does itintersect the beam path of the laser light between the laser devices andthe wavelength converting element. Optionally, the encapsulatingmaterial is molded over the device after wire bonding of the laserdevices, and no air gaps or voids are included.

In another embodiment, the light engine is encapsulated using a rigid,member such as a ceramic or metal housing. For example, a stamped metalwall could be provided with dimensions close to those of the outer edgeof the common substrate. The wall could be attached to the commonsubstrate and an airtight seal formed using epoxy or another glue, metalsolder, glass frit sealing and friction welding among other bondingtechniques. The top edge of the wall could, for example, be sealed byattaching a transparent cover. The transparent cover may be composed ofany transparent material, including silica-containing glass, sapphire,spinel, plastic, diamond and other various minerals. The cover may beattached to the wall using epoxy, glue, metal solder, glass frit sealingand friction welding among other bonding techniques appropriate for thecover material.

In some embodiments the enclosure may be fabricated directly on thecommon substrate using standard lithographic techniques similar to thoseused in processing of MEMS devices. Many light emitters such as laserdiodes could be fabricated on the same common substrate and, oncefabrication is complete, singulated into separate devices using sawing,laser scribing or a like process.

FIG. 19A is a side-view schematic diagram of a laser based white lightsource with an IR illumination capability operating in reflection modein an enclosed surface mount package according to an embodiment of thepresent invention. As seen in the figure, the surface mount devicepackage is comprised of a package base member configured as a supportmember. The phosphor plate overlies the support member and is configuredin an optical pathway of the light emission from one or more laser diodemembers. The one or more laser diode members are configured on anelevated mounting surface that is not parallel to the mounting surfacethat the phosphor plate is mounted on. The result is an angle ofincidence of the laser excitation beam on the phosphor plate. Thephosphor plate is configured in a reflection mode wherein the platereceives the emission from the laser diode member on a top excitationsurface and emits a visible light and an IR light from the same topsurface. A transparent window member is included to provide a sealaround the laser based visible and IR emitting source.

FIG. 19B is a side-view schematic diagram of a fiber-coupled laser basedwhite light source with an IR illumination capability operating inreflection mode in an enclosed package according to an embodiment of thepresent invention. As seen in the figure, the surface mount devicepackage is comprised of a package base member configured as a supportmember. The phosphor plate overlies the support member and is configuredin an optical pathway of the light emission from one or more opticalfiber members that transport the excitation emission from one or morelaser diodes into the package. The fiber is positioned at an off-normalangle relative to the that the phosphor plate such that the excitationbeam exciting the fiber is incident on a top surface of the phosphor.The phosphor plate is configured in a reflection mode wherein the platereceives the emission from the laser diode member on a top excitationsurface and emits a visible light and an IR light from the same topsurface.

Referring to FIGS. 17A, 17B, 18A, 18B, 18C, 19A, and 19B showing severalembodiments of the laser based white light source configured with an IRillumination source in a SMD type package. Optionally, the wedge-shapedmembers 1401, 1604, 1614, and 1616 in the SMD package are configuredsuch that the laser light from each of multiple laser devices isincident on the wavelength converting element 1406 or 1602 with an angleof 10 to 45 degrees from the plane of the wavelength convertingelement's upper. Optionally, the wavelength converting element 1602 isbonded to the common substrate 1601 using a solder material. Optionally,the bonded surface of the wavelength converting element 1602 is providedwith an adhesion promoting layer such as a Ti/Pt/Au metal stack.Optionally, the adhesion promoting layer includes as first layer that ishighly reflective. Optionally, the adhesion promoting layers could beAg/Ti/Pt/Au, where Ag is adjacent to the wavelength converting elementand provides a highly-reflective surface below the wavelength convertingelement. The laser devices are connected electrically to the backsidesolder pads using wire bonding between electrical contact pads on thelaser device chips and the top-side wire-bond pads on the commonsubstrate. Optionally, only one of the multiple laser devices in the SMDpackaged white light source is a blue pump light source with a centerwavelength of between 405 and 470 nm. Optionally, the first wavelengthconverting element is a YAG-based phosphor plate which absorbs the pumplight and emits a broader spectrum of yellow-green light such that thecombination of the pump light spectra and phosphor light spectraproduces a white light spectrum. The color point of the white light ispreferably located within du′v′ of less than 0.03 of the Planckianblackbody locus of points.

In some embodiments the laser based white light source configured withan IR illumination source is configured with an IR sensor or an IRimaging system. The IR illumination source of the present inventionwould be used to direct IR electromagnetic radiation toward a targetarea or subject and IR sensor or imaging system would be deployed todetect the presence, movement, or other characteristics of a subjectmatter or object within the illumination area. Once a certaincharacteristic was detected by the IR sensor, a response could betriggered. In one example, the visible laser based white light would betriggered to be activated to illuminate the target matter with visiblewhite light. In some embodiments according to the present invention aninfrared tracking, also known as infrared homing, is included whereinthe infrared electromagnetic radiation emitted from a target is used totrack the objects motion. Infrared is radiated strongly by hot bodiessuch as people, vehicles and aircraft.

Infrared waves are not visible to the human eye. In the electromagneticspectrum, infrared radiation can be found between the visible andmicrowave regions. The infrared waves typically have wavelengths between0.75 and 1000 μm. The infrared spectrum can be split into near IR, midIR and far IR. The wavelength region from 0.75 to 3 μm is known as thenear infrared region. The region between 3 and 6 μm is known as themid-infrared region, and infrared radiation which has a wavelengthgreater higher than 6 μm is known as far infrared.

Thermal imaging systems use mid- or long wavelength IR energy and areconsidered passive, sensing only differences in heat. These heatsignatures are then displayed on a screen, monitor, or some otherreadout device. Thermal imagers do not see reflected light and aretherefore not affected by surrounding light sources such as oncomingheadlights.

Night vision and other lowlight cameras rely on reflected ambient lightsuch as moonlight or starlight. Night vision is not effective when thereis too much light, but not enough light for you to see with the nakedeye such as during the twilight hours. Perhaps, even more limiting, thesensitivity of night vision imaging technology is limited if there isnot enough ambient visible light available since the imaging performanceof anything that relies on reflected light is limited by the amount andstrength of the light being reflected. In many instances there are nonatural sources of illumination available in places such as caves,tunnels, basements, etc. In these situations, active illumination withIR sources that are not detectable to the human eye, night visiongoggles, or silicon cameras can be used to illuminate an area or atarget. These active imaging systems include IR illumination sources togenerate their own reflected light by projecting a beam of near-IRenergy that can be detected in the imager when it is reflected from anobject. Such active IR systems can use short wavelength infrared lightto illuminate an area of interest wherein some of the IR energy isreflected back to a camera and interpreted to generate an image. Such“covert” illumination without detection from common imaging technologiesincluding visible light imaging technologies can be advantageous. Insome embodiments, active IR systems can use mid-IR or deep-IRillumination sources.

Since this technology relies on reflected IR light to make an image withconventional IR illumination sources such as LED illumination sources,the range and contrast of the imaging system can be limited. The laserbased white light system configured with an IR illumination sourceaccording to the present invention offers a superior illumination sourcethat can overcome these challenges of range and contrast. Since the IRillumination is originating from either directly from a highlydirectional IR emitting laser diode or from a laser diode excited IRemitting wavelength converter member, the IR emission can be orders ofmagnitude brighter than conventional LED IR emission. This 10 to 10,000×increased brightness using a laser-based IR illumination source canincrease the range by 10 to 1000× over LED sources and provide superiorcontrast.

IR detectors are used to detect the radiation which has been collected.In some embodiments, the current or voltage output from the detectors isvery small, requiring pre-amplifiers coupled with circuitry to furtherprocess the received signals. The two main types of IR detectors arethermal detectors and photodetectors. The response time and sensitivityof photonic detectors can be much higher, but often these have to becooled to reduce thermal noise. The materials in these aresemiconductors with narrow band gaps. Incident IR photons causeelectronic excitations. In photoconductive detectors, the resistivity ofthe detector element is monitored. Photovoltaic detectors contain a p-njunction or a p-i-n junction on which photoelectric current appears uponillumination.

In one embodiment, the detector technology used to generate theresulting image can be an IR photodiode which is sensitive to IR lightof the same wavelength as that emitted by the IR illumination source.When the reflected IR light is incident on the photodiode, aphotocurrent is generated which induces an output voltage proportionalto the magnitude of the IR light received. These infrared cameras shouldhave a high signal-to-noise ratio with a high sensitivity orresponsivity. In one example, an InGaAs based photodiode is used for theIR detector. In other examples, InAs based photodiodes, InSb basedphotodiodes, InAsSb based photodiodes, PbSe based photodiodes, or PbSbased photodiodes can be included. In some configurations according tothe present invention, photodiode arrays are included for IR detection.Additionally, avalanche photodiodes (APD) are included in the presentinvention. The detectors can be configured to operate as photovoltaic orphotoconductive conductors. In some examples according to the presentinvention, some combination of the described detector technologies areincluded two color detectors. In some examples amplifiers andphotomultipliers are included.

The thermal effects of the incident IR radiation can be followed throughmany temperature dependent phenomena. Bolometers and microbolometers arebased on changes in resistance. Thermocouples and thermopiles use thethermoelectric effect. Golay cells follow thermal expansion. In IRspectrometers the pyroelectric detectors are the most widespread.

In several preferred embodiments of the laser based white light sourceincluding an IR illumination source is configured for communication. Thecommunication could be intended for biological media such as humans suchas pedestrians, consumers, athletes, police officers and other publicservants, military, travelers, drivers, commuters, recreationactivities, or other living things such as animals, plants, or otherliving objects. The communication could also be intended for objectssuch as cars or any type of auto including autonomous examples,airplanes, drones or other aircraft, which could be autonomous, or anywide range of objects such as street signs, roadways, tunnels, bridges,buildings, interior spaces in offices and residential and objectscontained within, work areas, sports areas including arenas and fields,stadiums, recreational areas, and any other objects or areas. In somepreferred embodiments the smart light source is used in Internet ofThings (IoT), wherein the laser based smart light is used to communicatewith objects such as household appliances (i.e., refrigerator, ovens,stove, etc.), lighting, heating and cooling systems, electronics,furniture such as couches, chairs, tables, beds, dressers, etc.,irrigation systems, security systems, audio systems, video systems, etc.Clearly, the laser based smart lights can be configured to communicatewith computers, smart phones, tablets, smart watches, augmented reality(AR) components, virtual reality (VR) components, games including gameconsoles, televisions, and any other electronic devices.

According to some embodiments of the present invention, the laser lightsource can communicate with various methods. In one preferred method,the smart light is configured as a visible light communication (VLC)system such as a LiFi system wherein at least one spectral component ofthe electromagnetic radiation in the light source is modulated to encodedata such that the light is transmitting data. In some examples, aportion of the visible spectrum is modulated and in other examples anon-visible source such as an infrared or ultraviolet source is includedfor communication. The modulation pattern or format could be a digitalformat or an analog format, and would be configured to be received by anobject or device. In some embodiments, communication could be executedusing a spatial patterning of the light emission from the laser basedsmart light system. In an embodiment, a micro-display is used topixelate or pattern the light, which could be done in a rapid dynamicfashion to communicate continuously flowing information or wherein thepattern is periodically changed to a static pattern to communicate astatic message that could be updated. Examples of communication could beto inform individuals or crowds about upcoming events, what is containedinside a store, special promotions, provide instructions, education,sales, and safety. In an alternative embodiment, the shape or divergenceangle of the emission beam is changed to a spotlight from a diffuselight or vice versa using a micro-display or a tunable lens such as aliquid crystal lens. Examples of communication could be to direct anindividual or crowd, to warn about dangers, educate, or promote. In yetanother embodiment of laser light-based communication, the color of thesmart lighting system could be changed from a cool white to a warmwhite, or even to a single color such as red, green, blue, or yellow,etc.

It is to be understood that in embodiments, the VLC light engine is notlimited to a specific number of laser devices. In a specific embodiment,the light engine includes a single laser device acting as a “pump”light-source, and which is either a laser diode or SLED device emittingat a center wavelength between 390 nm and 480 nm. In some embodimentsthe gallium and nitrogen containing laser diode operates in the 480 nmto 540 nm range. In some embodiments the laser diode is comprised from aIII-nitride material emitting in the ultraviolet region with awavelength of about 270 nm to about 390 nm. Herein, a “pump”light-source is a laser diode or SLED device that illuminates aswavelength converting element such that a part or all laser light fromthe laser diode or SLED device is converted into longer wavelength lightby the wavelength converting element. The spectral width of the pumplight-source is preferably less than 2 nm, though widths up to 20 nmwould be acceptable. In another embodiment, the VLC light engineconsists of two or more laser or SLED “pump” light-sources emitting withcenter wavelengths between 380 nm and 480 nm, with the centerwavelengths of individual pump light sources separated by at least 5 nm.The spectral width of the laser light source is preferably less than 2nm, though widths up to 75% of the center wavelength separation would beacceptable. The pump light source illuminates a phosphor which absorbsthe pump light and reemits a broader spectrum of longer wavelengthlight. Each pump light source is individually addressable, such thatthey may be operated independently of one another and act as independentcommunication channels.

Encoding of information for communication by the laser or SLED can beaccomplished through a variety of methods. Most basically, the intensityof the LD or SLED could be varied to produce an analog or digitalrepresentation of an audio signal, video image or picture or any type ofinformation. An analog representation could be one where the amplitudeor frequency of variation of the LD or SLED intensity is proportional tothe value of the original analog signal.

A primary benefit of the present invention including a laser diode-basedor SLED-based lighting systems when applied to a LiFi or VLC applicationis that both laser diodes and SLEDs operate with stimulated emissionwherein the direct modulation rates are not governed by carrier lifetimesuch as LEDs, which operate with spontaneous emission. Specifically, themodulation rate or frequency response of LEDs is inversely proportionalto the carrier lifetime and proportional to the electrical parasitics(e.g., RC time constant) of the diode and device structure. Sincecarrier lifetimes are on the order of nanoseconds for LEDs, thefrequency response is limited to the MHz range, typically in the 100s ofMHz (i.e., 300-500 MHz). Additionally, since high power or mid powerLEDs typically used in lighting require large diode areas on the orderof 0.25 to 2 mm², the intrinsic capacitance of the diode is excessiveand can further limit the modulation rate. On the contrary, laser diodesoperate under stimulated emission wherein the modulation rates aregoverned by the photon lifetime, which is on the order of picoseconds,and can enable modulation rates in the GHz range, from about 1 to about30 GHz depending on the type of laser structure, the differential gain,the active region volume, and optical confinement factor, and theelectrical parasitics. As a result, VLC systems based on laser diodescan offer 10×, 100×, and potentially 1000× higher modulation rates, andhence data rates, compared to VLC systems based on LEDs. Since VLC(i.e., LiFi) systems in general can provide higher data rates than WiFisystems, laser based LiFi systems can enable 100× to 10,000× the datarate compared to conventional WiFi systems offering enormous benefitsfor delivering data in applications demand high data volumes such aswhere there are a large number of users (e.g., stadiums) and/or wherethe nature of the data being transferred requires a volume of bits(e.g., gaming).

Vertical cavity surface emitting lasers (VCSELs) are laser diode deviceswherein the optical cavity is orthogonal to the epitaxial growthdirection. These structures have very short cavity lengths dictated bythe epitaxial growth thickness wherein high reflectivity distributedbragg reflectors (DBR) terminating each end of the cavity. The extremelysmall cavity length and hence cavity area of VCSELs makes them ideal forhigh speed modulation, wherein 3 modulation bandwidths of greater than10 GHz, greater than 20 GHz, and greater than 30 GHz are possible. Insome embodiments of the present invention VCSELs can be included. SuchVCSELs may be based on GaN and related materials, InP and relatedmaterial, or GaAs and related materials.

Digital encoding is common encoding scheme where the data to betransmitted is represented as numerical information and then varying theLD or SLED intensity in a way that corresponds to the various values ofthe information. As an example, the LD or SLED could be turned fully onand off with the on and off states correlated to binary values or couldbe turned to a high intensity state and a low intensity state thatrepresent binary values. The latter would enable higher modulation ratesas the turn-on delay of the laser diode would be avoided. The LD or SLEDcould be operated at some base level of output with a small variation inthe output representing the transmitted data superimposed on the baselevel of output. This is analogous to having a DC offset or bias on aradio-frequency or audio signal. The small variation may be in the formof discrete changes in output that represent one or more bits of data,though this encoding scheme is prone to error when many levels of outputare used to more efficiently encode bits. For example, two levels may beused, representing a single binary digit or bit. The levels would beseparated by some difference in light output. A more efficient encodingwould use 4 discrete light output levels relative to the base level,enabling one value of light output to represent any combination of twobinary digits or bits. The separation between light output levels isproportional to n−1, where n is the number of light output levels.Increasing the efficiency of the encoding in this way results in smallerdifferences in the signal differentiating encoded values and thus to ahigher rate of error in measuring encoded values.

In some embodiments, additional beam shapers would be included betweenthe laser diode members and the wavelength converter element toprecondition the pump light beam before it is incident on the phosphor.For example, in a preferred embodiment the laser or SLED emission wouldbe collimated prior to incidence with the wavelength converter such thatthe laser light excitation spot would have a specified and controlledsize and location. The light signal then leaves the light engine andpropagates either through free-space or via a waveguide such as anoptical fiber. In an embodiment, the non-converted laser light isincident on the wavelength converting element 1527, however thenon-converted laser light is efficiently scattered or reflected by thewavelength converting element 1527 such that less than 10% of theincident light is lost to absorption by the wavelength convertingelement 1527.

Use of multiple lasers of same wavelength allows for running each laserat a lower power than what one would do with only one pump laser for afixed power of emitted white light spectrum. Addition of red and greenlasers which are not converted allow for adjusting the color point ofthe emitted spectrum. Given a single blue emitter, so long as theconversion efficiency of the wavelength converting element does notsaturate with pump laser intensity, the color point of the white lightspectrum is fixed at a single point in the color space which isdetermined by the color of the blue laser, the down-converted spectrumemitted by the wavelength converting element, and the ratio of the powerof the two spectra, which is determined by the down-conversionefficiency and the amount of pump laser light scattered by thewavelength converting element. By the addition of an independentlycontrolled green laser, the final color point of the spectrum can bepulled above the Planckian blackbody locus of points. By addition of anindependently controlled red laser, the final color point of thespectrum can be pulled below the Planckian blackbody locus of points. Bythe addition of independently controlled violet or cyan colored lasers,with wavelengths not efficiently absorbed by the wavelength convertingelement, the color point can be adjusted back towards the blue side ofthe color gamut. Since each laser is independently driven, thetime-average transmitted power of each laser can be tailored to allowfor fine adjustment of the color point and CRI of the final white lightspectrum.

Optionally, multiple blue pump lasers might be used with respectivecenter wavelengths of 420, 430, and 440 nm while non-converted green andred laser devices are used to adjust the color point of the devicesspectrum. Optionally, the non-converted laser devices need not havecenter wavelengths corresponding to red and green light. For example,the non-converted laser device might emit in the infra-red region atwavelengths between 800 nm and 2 microns. Such a light engine would beadvantageous for communication as the infra-red device, while not addingto the luminous efficacy of the white light source, or as a visiblelight source with a non-visible channel for communications. This allowsfor data transfer to continue under a broader range of conditions andcould enable for higher data rates if the non-visible laser configuredfor data transmission was more optimally suited for high speedmodulation such as a telecom laser or vertical cavity surface emittinglaser (VCSEL). Another benefit of using a non-visible laser diode forcommunication allows the VLC-enabled white light source to use anon-visible emitter capable of effectively transmitting data even whenthe visible light source is turned off for any reason in applications.

In some embodiments, the white light source is configured to be a smartlight source having a beam shaping optical element. Optionally, the beamshaping optical element provides an optical beam where greater than 80%of the emitted light is contained within an emission angle of 30degrees. Optionally, the beam shaping element provides an optical beamwhere greater than 80% of the emitted light is contained within anemission angle of 10 degrees. Optionally, the white light source can beformed within the commonly accepted standard shape and size of existingMR, PAR, and AR111 lamps. Optionally, the white light source furthercontains an integrated electronic power supply to electrically energizethe laser-based light module. Optionally, the white light source furthercontains an integrated electronic power supply with input power withinthe commonly accepted standards. Of course, there can be othervariations, modifications, and alternatives.

In some embodiments, the smart light source containing at least alaser-based light module has one or more beam steering elements toenable communication. Optionally, the beam steering element provides areflective element that can dynamically control the direction ofpropagation of the emitted laser light. Optionally, the beam steeringelement provides a reflective element that can dynamically control thedirection of propagation of the emitted laser light and the lightemitted from the wavelength converting element. Optionally, the smartlight white light source further contains an integrated electronic powersupply to electrically energize the beam steering elements. Optionally,the smart light white light source further contains an integratedelectronic controller to dynamically control the function of the beamsteering elements.

According to an embodiment, the present invention provides a dynamiclaser-based light source or light projection apparatus including amicro-display element to provide a dynamic beam steering, beampatterning, or beam pixelating affect. Micro-displays such as amicroelectromechanical system (MEMS) scanning mirror, or “flyingmirror”, a digital light processing (DLP) chip or digital mirror device(DMD), or a liquid crystal on silicon (LCOS) can be included todynamically modify the spatial pattern and/or color of the emittedlight. In one embodiment the light is pixelated to activate certainpixels and not activate other pixels to form a spatial pattern or imageof white light. In another example, the dynamic light source isconfigured for steering or pointing the light beam. The steering orpointing can be accomplished by a user input configured from a dial,switch, or joystick mechanism or can be directed by a feedback loopincluding sensors.

In an embodiment, a laser driver module is provided. Among other things,the laser driver module is adapted to adjust the amount of power to beprovided to the laser diode. For example, the laser driver modulegenerates a drive current based on pixels from digital signals such asframes of images, the drive currents being adapted to drive a laserdiode. In a specific embodiment, the laser driver module is configuredto generate pulse-modulated light signal at a frequency range of about50 MHz to 100 GHz.

In an alternative embodiment, DLP or DMD micro-display chip is includedin the device and is configured to steer, pattern, and/or pixelate abeam of light by reflecting the light from a 2-dimensional array ofmicro-mirrors corresponding to pixels at a predetermined angle to turneach pixel on or off. In one example, the DLP or DMD chip is configuredto steer a collimated beam of laser excitation light from the one ormore laser diodes to generate a predetermined spatial and/or temporalpattern of excitation light on the wavelength conversion or phosphormember. At least a portion of the wavelength converted light from thephosphor member could then be recollimated or shaped using a beamshaping element such as an optic. In this example the micro-display isupstream of the wavelength converter member in the optical pathway. In asecond example the DLP or DMD micro-display chip is configured to steera collimated beam of at least a partially wavelength converted light togenerate a predetermined spatial and/or temporal pattern of convertedlight onto a target surface or into a target space. In this example themicro-display is downstream of the wavelength converter member in theoptical pathway. DLP or DMD micro-display chips are configured fordynamic spatial modulation wherein the image is created by tiny mirrorslaid out in an array on a semiconductor chip such as a silicon chip. Themirrors can be positionally modulated at rapid rates to reflect lighteither through an optical beam shaping element such as a lens or into abeam dump. Each of the tiny mirrors represents one or more pixelswherein the pitch may be 5.4 μm or less. The number of mirrorscorresponds or correlates to the resolution of the projected image.Common resolutions for such DLP micro-display chips include 800×600,1024×768, 1280×720, and 1920×1080 (HDTV), and even greater.

According to an embodiment, the present invention provides a dynamiclaser-based light source or light projection apparatus including ahousing having an aperture. The apparatus can include an input interfacefor receiving a signal to activate the dynamic feature of the lightsource. The apparatus can include a video or signal processing module.Additionally, the apparatus includes a light source based on a lasersource. The laser source includes a violet laser diode or a blue laserdiode. The dynamic light feature output comprised from a phosphoremission excited by the output beam of a laser diode, or a combinationof a laser diode and a phosphor member. The violet or blue laser diodeis fabricated on a polar, nonpolar, or semipolar oriented Ga-containingsubstrate. The apparatus can include a laser driver module coupled tothe laser source. The apparatus can include a digital light processing(DLP) chip comprising a digital mirror device. The digital mirror deviceincludes a plurality of mirrors, each of the mirrors corresponding topixels of the frames of images. The apparatus includes a power sourceelectrically coupled to the laser source and the digital lightprocessing chip.

The apparatus can include a laser driver module coupled to the lasersource. The apparatus includes an optical member provided withinproximity of the laser source, the optical member being adapted todirect the laser beam to the digital light processing chip. Theapparatus includes a power source electrically coupled to the lasersource and the digital light processing chip. In one embodiment, thedynamic properties of the light source may be initiated by the user ofthe apparatus. For example, the user may activate a switch, dial,joystick, or trigger to modify the light output from a static to adynamic mode, from one dynamic mode to a different dynamic mode, or fromone static mode to a different static mode.

In an alternative embodiment, a liquid crystal on silicon (LCOS)micro-display chip is included in the device and is configured to steer,pattern, and/or pixelate a beam of light by reflecting or absorbing thelight from a 2-dimensional array of liquid crystal mirrors correspondingto pixels at a predetermined angle to turn each pixel on or off In oneexample, the LCOS chip is configured to steer a collimated beam of laserexcitation light from the one or more laser diodes to generate apredetermined spatial and/or temporal pattern of excitation light on thewavelength conversion or phosphor member. At least a portion of thewavelength converted light from the phosphor member could then berecollimated or shaped using a beam shaping element such as an optic. Inthis example the micro-display is upstream of the wavelength convertermember in the optical pathway. In a second example the LCOSmicro-display chip is configured to steer a collimated beam of at leasta partially wavelength converted light to generate a predeterminedspatial and/or temporal pattern of converted light onto a target surfaceor into a target space. In this example the micro-display is downstreamof the wavelength converter member in the optical pathway. The formerexample is the preferred example since LCOS chips are polarizationsensitive and the output of laser diodes is often highly polarized, forexample greater than 70%, 80%, 90%, or greater than 95% polarized. Thishigh polarization ratio of the direct emission from the laser sourceenables high optical throughput efficiencies for the laser excitationlight compared to LEDs or legacy light sources that are unpolarized,which wastes about half of the light.

LCOS micro-display chips are configured spatial light modulation whereinthe image is created by tiny active elements laid out in an array on asilicon chip. The elements reflectivity is modulated at rapid rates toselectively reflect light through an optical beam shaping element suchas a lens. The number of elements corresponds or correlates to theresolution of the projected image. Common resolutions for such LCOSmicro-display chips include 800×600, 1024×768, 1280×720, and 1920×1080(HDTV), and even greater.

Optionally, the partially converted light emitted from the wavelengthconversion element results in a color point, which is white inappearance. Optionally, the color point of the white light is located onthe Planckian blackbody locus of points. Optionally, the color point ofthe white light is located within du′v′ of less than 0.010 of thePlanckian blackbody locus of points. Optionally, the color point of thewhite light is preferably located within du′v′ of less than 0.03 of thePlanckian blackbody locus of points. Optionally, the pump light sourcesare operated independently, with their relative intensities varied todynamically alter the color point and color rendering index (CRI) of thewhite light.

In several preferred embodiments one or more beam shaping elements areincluded in the present invention. Such beam shaping elements could beincluded to configure the one or more laser diode excitation beams inthe optical pathway prior to incidence on the phosphor or wavelengthconversion member. In some embodiments the beam shaping elements areincluded in the optical pathway after at least a portion of the laserdiode excitation light is converted by the phosphor or wavelengthconversion member. In additional embodiments the beam shaping elementsare included in the optical pathway of the non-converted laser diodelight. Of course, in many preferred embodiments, a combination of one ormore of each of the beam shaping elements is included in the presentinvention.

In some embodiments, a laser diode output beam must be configured to beincident on the phosphor material to excite the phosphor. In someembodiments, the laser beam may be directly incident on the phosphor andin other embodiments the laser beam may interact with an optic,reflector, or other object to manipulate or shape the beam prior toincidence on the phosphor. Examples of such optics include, but are notlimited to ball lenses, aspheric collimator, aspheric lens, fast or slowaxis collimators, dichroic mirrors, turning mirrors, optical isolators,but could be others. In some embodiments, other optics can be includedin various combinations for the shaping, collimating, directing,filtering, or manipulating of the optical beam. Examples of such opticsinclude, but are not limited to re-imaging reflectors, ball lenses,aspheric collimator, dichroic mirrors, turning mirrors, opticalisolators, but could be others.

In some embodiments, the converted light such as a white light source iscombined with one or more optical members to manipulate the generatedwhite light. In an example the converted light source such as the whitelight source could serve in a spotlight system such as a flashlight,spotlight, automobile headlamp or any direction light applications wherethe light must be directed or projected to a specified location or area.In one embodiment a reflector is coupled to the white light source.Specifically, a parabolic (or paraboloid or paraboloidal) reflector isdeployed to project the white light. By positioning the white lightsource in the focus of a parabolic reflector, the plane waves will bereflected and propagate as a collimated beam along the axis of theparabolic reflector. In another example a lens is used to collimate thewhite light into a projected beam. In one example a simple aspheric lenswould be positioned in front of the phosphor to collimate the whitelight. In another example, a total internal reflector optic is used forcollimation. In other embodiments other types of collimating optics maybe used such as spherical lenses or aspherical lenses. In severalembodiments, a combination of optics is used.

In some embodiments, the smart white light source containing at least alaser-based light module includes a beam shaping element. Optionally,the beam shaping element provides an optical beam where greater than 80%of the emitted light is contained within an emission angle of 30degrees. Optionally, the beam shaping element provides an optical beamwhere greater than 80% of the emitted light is preferably containedwithin an emission angle of 10 degrees. Optionally, the beam shapingelement provides an optical beam where greater than 80% of the emittedlight is preferably contained within an emission angle of 5 degrees. Insome embodiments collimating optics are used such as parabolicreflectors, total internal reflector (TIR) optics, diffractive optics,other types of optics, and combinations of optics.

Optionally, the smart white light source can be formed within thecommonly accepted standard shape and size of existing MR, PAR, and AR111lamps. Optionally, the solid-state white light source further containsan integrated electronic power supply to electrically energize thelaser-based light module. Optionally, the solid-state white light sourcefurther contains an integrated electronic power supply with input powerwithin the commonly accepted standards. Of course, there can be othervariations, modifications, and alternatives.

In an embodiment, the apparatus is capable of conveying information tothe user or another observer through the means of dynamically adjustingcertain qualities of the projected light. Such qualities include spotsize, shape, hue, and color-point as well as through independent motionof the spot. As an example, the apparatus may convey information bydynamically changing the shape of the spot. In an example, the apparatusis used as a flash-light or bicycle light, and while illuminating thepath in front of the user it may convey directions or informationreceived from a paired smart phone application. Changes in the shape ofthe spot which could convey information include, among others: formingthe spot into the shape of an arrow that indicates which direction theuser should walk along to follow a predetermined path and forming thespot into an icon to indicate the receipt of an email, text message,phone call or other push notification. The white light spot may also beused to convey information by rendering text in the spot. For example,text messages received by the user may be displayed in the spot. Asanother example, embodiments of the apparatus including mechanisms foraltering the hue or color point of the emitted light spectrum couldconvey information to the user via a change in these qualities. Forexample, the aforementioned bike light providing directions to the usermight change the hue of the emitted light spectrum from white to redrapidly to signal that the user is nearing an intersection or stop-signthat is beyond the range of the lamp.

In a specific embodiment of the present invention including a dual bandlight source capable of emission in the visible and the IR wavelengthbands, one or more emission bands from the light source is activated bya feedback loop including a sensor to create a dynamic illuminationsource capable of alternating the activation of the illumination bands.Such sensors may be selected from, but not limited to an IR imaging unitincluding an IR camera or focal plane array, microphone, geophone,hydrophone, a chemical sensor such as a hydrogen sensor, CO₂ sensor, orelectronic nose sensor, flow sensor, water meter, gas meter, Geigercounter, altimeter, airspeed sensor, speed sensor, range finder,piezoelectric sensor, gyroscope, inertial sensor, accelerometer, MEMSsensor, Hall effect sensor, metal detector, voltage detector,photoelectric sensor, photodetector, photoresistor, pressure sensor,strain gauge, thermistor, thermocouple, pyrometer, temperature gauge,motion detector, passive infrared sensor, Doppler sensor, biosensor,capacitance sensor, video sensor, transducer, image sensor, infraredsensor, radar, SONAR, LIDAR, or others.

In one example, a dynamic illumination feature including a feedback loopwith an IR sensor to detect motion or an object. The dynamic lightsource is configured to generate a visible illumination on the object orlocation where the motion is detected by sensing the spatial position ofthe motion and steering the output beam to that location. In anotherexample of a dynamic light feature including a feedback loop with asensor, such as an accelerometer, is included. The accelerometer isconfigured to anticipate where the laser light source apparatus ismoving toward and steer the output beam to that location even before theuser of the apparatus can move the light source to be pointing at thedesired location. Of course, these are merely examples ofimplementations of dynamic light sources with feedback loops includingsensors. There can be many other implementations of this inventionconcept that includes combining dynamic light sources with sensors.

FIG. 20A is a functional block diagram for a laser-based white lightsource containing a gallium and nitrogen containing violet or blue pumplaser and a wavelength converting element to generate a white lightemission, an infrared emitting laser diode to generate an IR emissionaccording to an embodiment of the present invention, configured withsensors to form feedback loops. This diagram is merely an example, whichshould not unduly limit the scope of the claims. Referring to FIG. 20A,a blue or violet laser device emitting a spectrum with a center pointwavelength between 390 and 480 nm is provided. The light from the bluelaser device is incident on a wavelength converting element, whichpartially or fully converts the blue light into a broader spectrum oflonger wavelength light such that a white light spectrum is produced. Afirst laser driver is provided which powers the gallium and nitrogencontaining laser device to excite the visible emitting wavelengthmember. Additionally, an IR emitting laser device is included togenerate an IR illumination. The directional IR electromagneticradiation from the laser diode is incident on the wavelength convertingelement wherein it is reflected from or transmitted through thewavelength converting element such that it follows the same optical pathas the white light emission. A second laser driver is included to powerthe IR emitting laser diode and deliver a controlled amount of currentat a sufficiently high voltage to operate the IR laser diode.

The visible and IR emitting illumination source according to the presentinvention and shown in FIG. 20A is equipped with sensors configured toprovide an input to the first and/or the second laser drivers. In oneexample, the first laser driver is configured with an IR sensor thatdetects motion or objects using the IR illumination source. Once adetection is triggered using the IR illumination source, the first laserdriver activates the first laser diode to generate a white light toshine a visible light on the object or target. There are many exampleswhere it would be useful to covertly detect an object using IRillumination such that it could not be detected by animals or humans.

According to this embodiment shown in FIG. 20A, the IR emission includesa peak wavelength in the 700 nm to 1100 nm range based on gallium andarsenic material system [eg GaAs] for near-IR illumination, or a peakwavelength in the 1100 to 2500 nm range based on an indium andphosphorous containing material system (e.g., InP) for eye-safewavelength IR illumination, or in the 2500 nm to 15000 nm wavelengthrange based on quantum cascade laser technology for mid-IR thermalimaging. Optionally, the one or more beam shaping optical elements canbe one selected from slow axis collimating lens, fast axis collimatinglens, aspheric lens, ball lens, total internal reflector (TIR) optics,parabolic lens optics, refractive optics, or a combination of above.

Of course, any type of sensor could be configured with the presentinvention to induce a visible or IR illumination response when thesensor was triggered or tripped. Further elements could be incorporatedwith present invention including sensors. In one embodiment a beamsteering element such as a MEMS mirror or DLP is used to pattern ordirect the light onto a specific area or a specific object that could bemoving. By using a motion sensor or the IR sensor the illuminationsource configured with the beam steering element could be configured totrack the object with visible light and/or with IR illumination. In ascenario where the user did not want the target matter to be aware oftheir presence, the user could track with the IR illumination. In ascenario where the user did want the subject to be aware of theirpresence, they could track the subject with visible light. In manyjurisdictions, it is important to have photographs or other images undervisible light, in which case the visible illumination source would beilluminated. In some embodiments, filters may be used to selectivelyfilter the visible light, to selectively filter the IR illumination,and/or to selectively filter both the visible light and the IRillumination.

In one embodiment according to the present invention a LiFi or VLCcapability is included with the laser based visible and IR illuminationsource. In one example, the LiFi capability could be configured totransmit data to a target subject in its field of view once a certaindetection or sensor stimulus was triggered. The data could be targetedbased on IR sensor input or other sensor input such as a visible/IRcamera. In another example, the LiFi or VLC function is used to transmitdata to the user or another individual. In one example, the data beingtransmitted is the IR or visible imagery data acquired by the apparatus.Of course, there can be other applications and examples of the presentinvention that includes a LiFi or VLC capability.

In one embodiment according to the present invention a spatial sensingsystem that uses the gallium and nitrogen containing laser diode and/oran included IR emitting laser diode is configured with the laser basedvisible and IR illumination source. In one example, the spatial sensingcapability could be configured as a depth detector using a time offlight calculation. See U.S. application Ser. No. 15/841,053, filed Dec.13, 2017, the contents of which are incorporated herein by reference.

In some embodiments, the invention may be applicable as a visible lightcommunication transceiver for bi-directional communication. Optionally,the transceiver also contains a detector including a photodiode,avalanche photodiode, photomultiplier tube or other means of convertinga light signal to electrical energy. The detector is connected to themodem. In this embodiment the modem is also capable of decoding detectedlight signals into binary data and relaying that data to a controlsystem such as a computer, cellphone, wrist-watch, or other electronicdevice.

In some embodiments, the present invention provides a smart whitelight-source to be used on automotive vehicles for illumination of theexterior environment of the vehicle. An exemplary usage would be as aparking light, headlight, fog-light, signal-light or spot-light. In anembodiment, a lighting apparatus is provided including a housing havingan aperture. Additionally, the lighting apparatus includes one or morepump light sources including one or more blue lasers or blue SLEDsources. The individual blue lasers or SLEDs have an emission spectrumwith center wavelength within the range 400 to 480 nm. The one or moreof the pump light sources emitting in the blue range of wavelengthsilluminates a wavelength converting element which absorbs part of thepump light and reemits a broader spectrum of longer wavelength light.Each pump light source is configured such that both light from thewavelength converting element and light directly emitted from the one ormore light sources being combined as a white light spectrum. Thelighting apparatus further includes optical elements for focusing andcollimating the white light and shaping the white light spot.

In this smart lighting apparatus, each pump light source isindependently addressable, and is controlled by a laser driver moduleconfigured to generate pulse-modulated light signal at a frequency rangeof between 10 MHz and 100 GHz. The laser driver includes an inputinterface for receiving digital or analog signals from sensors andelectronic controllers in order to control the modulation of the pumplaser sources for the transmission of data. The lighting apparatus cantransmit data about the vehicle or fixture to which it is attached viathe modulation of the blue or violet lasers or SLED sources to othervehicles which have appropriately configured VLC receivers. For example,the white light source could illuminate oncoming vehicles. Optionally,it could illuminate from behind or sides vehicles travelling in the samedirection. As an example, the lighting apparatus could illuminateVLC-receiver enabled road signs, road markings, and traffic signals, aswell as dedicated VLC receivers installed on or near the highway. Thelighting apparatus would then broadcast information to the receivingvehicles and infrastructure about the broadcasting vehicle. Optionally,the lighting apparatus could transmit information on the vehicle'slocation, speed and heading as well as, in the case of autonomous orsemiautonomous vehicles, information about the vehicle's destination orroute for purposes of efficiently scheduling signal light changes orcoordinating cooperative behavior, such as convoying, between autonomousvehicles.

In some embodiments, the present invention provides a communicationdevice which can be intuitively aimed. An example use of thecommunication device would be for creation of temporary networks withhigh bandwidth in remote areas such as across a canyon, in a ravine,between mountain peaks, between buildings separated by a large distanceand under water. In these locations, distances may be too large for astandard wireless network or, as in the case of being under water, radiofrequency communications may be challenging due to the absorption ofradio waves by water. The communication device includes a housing havingan aperture. Additionally, the communication device includes one or moreblue laser or blue SLED source. The individual blue lasers or SLEDs havean emission spectrum with center wavelength within the range 400 to 480nm. One or more of the light sources emitting in the blue range ofwavelengths illuminates a wavelength converting element which absorbspart of the pump light and reemits a broader spectrum of longerwavelength light. The light source is configured such that both lightfrom the wavelength converting element and the plurality of lightsources are emitted as a white light spectrum. The communication deviceincludes optical elements for focusing and collimating the white lightand shaping the white light spot. Optionally, each light source in thecommunication device is independently addressable, and is controlled bya driver module configured to generate pulse-modulated light signal at amodulation frequency range of between 10 MHz and 100 GHz. The drivermodule includes an input interface for receiving digital or analogsignals from sensors and electronic controllers in order to control themodulation of the laser sources for the transmission of data.

The communication device includes one or more optical detectors to actas VLC-receivers and one or more band-pass filters for differentiatingbetween two or more of the laser or SLED sources. Optionally, aVLC-receiver may detect VLC signals using multiple avalanche photodiodescapable of measuring pulse-modulated light signals at a frequency rangeof about 50 MHz to 100 GHz. Optionally, the communication devicecontains one or more optical elements, such as mirrors or lenses tofocus and collimate the light into a beam with a divergence of less than5 degrees in a less preferred case and less than 2 degrees in a mostpreferred case. Two such apparatuses would yield a spot size of betweenroughly 3 and 10 meters in diameter at a distance of 100 to 300 meters,respectively, and the focused white light spot would enable operators toaim the VLC-transceivers at each other even over long distances simplyby illuminating their counterpart as if with a search light.

In some embodiments, the communication device disclosed in the presentinvention can be applied as flash sources such as camera flashes thatcarrying data information. Data could be transmitted through the flashto convey information about the image taken. For example, an individualmay take a picture in a venue using a camera phone configured with aVLC-enabled solid-state light-source in accordance with an embodiment ofthis invention. The phone transmits a reference number to VLC-receiversinstalled in the bar, with the reference number providing a method foridentifying images on social media websites taken at a particular timeand venue.

In some embodiments, the present invention provides a projectionapparatus. The projection apparatus includes a housing having anaperture. The apparatus also includes an input interface for receivingone or more frames of images. The apparatus includes a video processingmodule. Additionally, the apparatus includes one or more blue laser orblue SLED sources disposed in the housing. The individual blue lasers orSLEDs have an emission spectrum with center wavelength within the range400 to 480 nm. One or more of the light sources emitting in the bluerange of wavelengths illuminates a wavelength converting element whichabsorbs part of the pump light and reemits a broader spectrum of longerwavelength light. The light source is configured such that both lightfrom the wavelength converting element and the plurality of lightsources are emitted as a white light spectrum. Additionally, theapparatus includes optical elements for focusing and collimating thewhite light and shaping the white light spot. In this apparatus, eachlight source is independently addressable, and is controlled by a laserdriver module configured to generate pulse-modulated light signal at amodulation frequency range of between 10 MHz and 100 GHz. The laserdriver also includes an input interface for receiving digital or analogsignals from sensors and electronic controllers in order to control themodulation of the laser sources for the transmission of data.Furthermore, the apparatus includes a power source electrically coupledto the laser source and the digital light processing chip. Manyvariations of this embodiment could exist, such as an embodiment wherethe green and blue laser diode share the same substrate or two or moreof the different color lasers could be housed in the same packaged. Theoutputs from the blue, green, and red laser diodes would be combinedinto a single beam.

Fiber scanner has certain performance advantages and disadvantages overscanning mirror as the beam steering optical element in the dynamiclight source. Scanning mirror appears to have significantly moreadvantages for display and imaging applications. For example, thescanning frequency can be achieved much higher for scanning mirror thanfor fiber scanner. Mirror scanner may raster at near 1000 kHz withhigher resolution (<1 μm) but without 2D scanning limitation while fiberscanner may only scan at up to 50 kHz with 2D scanning limitation.Additionally, mirror scanner can handle much higher light intensity thanfiber scanner. Mirror scanner is easier to be physically set up withlight optimization for white light or RGB light and incorporated withphotodetector for image, and is less sensitive to shock and vibrationthan fiber scanner. Since light beam itself is directly scanned inmirror scanner, no collimation loss, AR loss, and turns limitationexist, unlike the fiber itself is scanned in fiber scanner which carriescertain collimation loss and AR loss over curved surfaces. Of course,fiber scanner indeed is advantageous in providing much larger angulardisplacement (near 80 degrees) over that (about +/−20 degrees) providedby mirror scanner.

This white light or multi-colored dynamic image projection technologyaccording to this invention enables smart lighting benefits to the usersor observers. This embodiment of the present invention is configured forthe laser-based light source to communicate with users, items, orobjects in two different methods wherein the first is through VLCtechnology such as LiFi that uses high-speed analog or digitalmodulation of an electromagnetic carrier wave within the system, and thesecond is by the dynamic spatial patterning of the light to createvisual signage and messages for the viewers to see. These two methods ofdata communication can be used separately to perform two distinctcommunication functions such as in a coffee shop or office setting wherethe VLC/LiFi function provides data to users' smart phones and computersto assist in their work or internet exploration while the projectedsignage or dynamic light function communicates information such asmenus, lists, directions, or preferential lighting to inform, assist, orenhance users experience in their venue.

In another aspect, the present invention provides a dynamic light sourceor “light-engine” that can function as a white light source for generallighting applications with tunable colors.

In an embodiment, the light-engine consists of two or more lasers orSLED light sources. At least one of the light sources emits a spectrumwith a center wavelength in the range of 380-450 nm. At least one of thelight sources emits a spectrum with a center wavelength in the range of450-540 nm. In some embodiments the laser diode is comprised from aIII-nitride material emitting in the ultraviolet region with awavelength of about 270 nm to about 390 nm. This embodiment isadvantageous in that for many phosphors in order to achieve a particularcolor point, there will be a significant gap between the wavelength ofthe laser light source and the shortest wavelength of the spectrumemitted by the phosphor. By including multiple blue lasers ofsignificantly different wavelengths, this gap can be filled, resultingin a similar color point with improved color rendering.

In an embodiment, the green and red laser light beams are incident onthe wavelength converting element in a transmission mode and arescattered by the wavelength converting element. In this embodiment thered and green laser light is not strongly absorbed by the wavelengthconverting element.

In and embodiment, the wavelength converting element consists of aplurality of regions comprised of varying composition or colorconversion properties. For example, the wavelength converting elementmay be comprised by a plurality of regions of alternating compositionsof phosphor. One composition absorbs blue or violet laser light in therange of wavelengths of 385 to 450 nm and converts it to a longerwavelength of blue light in the wavelength range of 430 nm to 480 nm. Asecond composition absorbs blue or violet laser light and converts it togreen light in the range of wavelengths of 480-550 nm. A thirdcomposition absorbs blue or violet laser light and converts it to redlight in the range of wavelengths of 550 to 670 nm. Between the laserlight source and the wavelength converting element is a beam steeringmechanism such as a MEMS mirror, rotating polygonal mirror, mirrorgalvanometer, or the like. The beam steering element scans a violet orblue laser spot across the array of regions on the wavelength convertingelement and the intensity of the laser is synced to the position of thespot on the wavelength converting element such that red, green and bluelight emitted or scattered by the wavelength converting element can bevaried across the area of the wavelength converting element.

In an embodiment, the phosphor elements are single crystal phosphorplatelets.

In an embodiment, the phosphor elements are regions of phosphor powdersintered into platelets or encapsulated by a polymer or glassy binder.

In another embodiment, the plurality of wavelength converting regionscomprising the wavelength converting element are composed of an array ofsemiconductor elements such as InGaN, GaN single or multi-quantum wellsfor the production of blue or green light and single andmulti-quantum-well structures composed of various compositions ofAlInGaAsP for production of yellow red light or infrared light, althoughthis is merely an example, which should not unduly limit the scope ofthe claims. One of ordinary skill in the art would recognize otheralternative semiconductor materials or light-converting structures.

In another embodiment, the plurality of wavelength converting regionscomprising the wavelength converting element are composed of an array ofsemiconductor elements such as InGaN GaN quantum dots for the productionof blue, red or green light and quantum dots composed of variouscompositions of AlInGaAsP for production of yellow and red light,although this is merely an example, which should not unduly limit thescope of the claims. One of ordinary skill in the art would recognizeother alternative semiconductor materials or light-convertingstructures.

In another embodiment, the wavelength converting element also containsregions of non-wavelength converting material that scatters the laserlight. The advantage of this configuration is that the blue laser lightis diffusely scattered without conversion losses, thereby improving theefficiency of the overall light source. Examples of such non-convertingbut scattering materials are: granules of wide-bandgap ceramics ordielectric materials suspended in a polymer or glassy matrix,wide-bandgap ceramics or dielectric materials with a roughened surface,a dichroic mirror coating overlaid on a roughened or patterned surface,or a metallic mirror or metallic-dielectric hybrid mirror deposited on arough surface.

In a specific embodiment, the input to the laser driver is a digital oranalog signal provided by one or more sensors.

In a specific embodiment, the output from the sensors is measured orread by a microcontroller or other digital circuit which outputs adigital or analog signal which directs the modulation of the laserdriver output based on the input signal from the sensors.

In a specific embodiment, the input to the driver is a digital or analogsignal provided by a microcontroller or other digital circuit based oninput to the microcontroller or digital circuit from one or moresensors.

Optionally, sensors used in the smart-lighting system may includesensors measuring atmospheric and environmental conditions such aspressure sensors, thermocouples, thermistors, resistance thermometers,chronometers or real-time clocks, humidity sensor, ambient light meters,pH sensors, infra-red thermometers, dissolved oxygen meters,magnetometers and hall-effect sensors, colorimeters, soil moistersensors, and microphones among others.

Optionally, sensors used in the smart-lighting system may includesensors for measuring non-visible light and electromagnetic radiationsuch as UV light sensors, infra-red light sensors, infra-red cameras,infra-red motion detectors, RFID sensors, and infra-red proximitysensors among others.

Optionally, sensors used in the smart-lighting system may includesensors for measuring forces such as strain gages, load cells, forcesensitive resistors and piezoelectric transducers among others.

Optionally, sensors used in the smart-lighting system may includesensors for measuring aspects of living organisms such as fingerprintscanner, pulse oximeter, heart-rate monitors, electrocardiographysensors, electroencephalography sensors and electromyography sensorsamong others.

In an embodiment, the dynamic properties of the light source may beinitiated by the user of the apparatus. For example, the user mayactivate a switch, dial, joystick, or trigger to modify the light outputfrom a static to a dynamic mode, from one dynamic mode to a differentdynamic mode, or from one static mode to a different static mode.

In one example of the smart-lighting system, it includes a dynamic lightsource configured in a feedback loop with a sensor, for example, amotion sensor, being provided. The dynamic light source is configured toilluminate specific locations by steering the output of the white lightbeam in the direction of detected motion. In another example of adynamic light feature including a feedback loop with a sensor, anaccelerometer is provided. The accelerometer is configured to measurethe direction of motion of the light source. The system then steers theoutput beam towards the direction of motion. Such a system could be usedas, for example, a flashlight or hand-held spot-light or head-mountsecurity light. Of course, these are merely examples of implementationsof dynamic light sources with feedback loops including sensors. Therecan be many other implementations of this invention concept thatincludes combining dynamic light sources with sensors.

According to an embodiment, the present invention provides a dynamiclaser-based light source or light projection apparatus that is spatiallytunable. The apparatus includes a housing with an aperture to hold alight source having an input interface for receiving a signal toactivate the dynamic feature of the light source. Optionally, theapparatus can include a video or signal processing module. Additionally,the apparatus includes a laser source disposed in the housing with anaperture. The laser source includes one or more of a violet laser diodeor blue laser diode. The dynamic light source features output comprisedfrom the laser diode light spectrum and a phosphor emission excited bythe output beam of a laser diode. The violet or blue laser diode isfabricated on a polar, nonpolar, or semipolar oriented Ga-containingsubstrate. The apparatus can include mirror galvanometer or amicroelectromechanical system (MEMS) scanning mirror, or “flyingmirror”, configured to project the laser light or laser pumped phosphorwhite light to a specific location in the outside world. By rasteringthe laser beam using the MEMS mirror a pixel in two dimensions can beformed to create a pattern or image. The apparatus can also include anactuator for dynamically orienting the apparatus to project the laserlight or laser pumped phosphor white light to a specific location in theoutside world.

According to an embodiment, the present invention provides a dynamiclight source or “light-engine” that can function as a white light sourcefor general lighting applications with tunable colors. The light-engineconsists of three or more laser or SLED light sources. At least onelight source emits a spectrum with a center wavelength in the range of380-480 nm and acts as a blue light source. At least one light emits aspectrum with a center wavelength in the range of 480-550 nm and acts asa green light source. At least one light emits a spectrum with a centerwavelength in the range 600-670 nm and acts as a red light source. Eachlight source is individually addressable, such that they may be operatedindependently of one another and act as independent communicationchannels, or in the case of multiple emitters in the red, green or bluewavelength ranges the plurality of light sources in each range may beaddressed collectively, though the plurality of sources in each rangeare addressable independently of the sources in the other wavelengthranges. One or more of the light sources emitting in the blue range ofwavelengths illuminates a wavelength converting element which absorbspart of the pump light and reemits a broader spectrum of longerwavelength light. The light engine is configured such that both lightfrom the wavelength converting element and the plurality of lightsources are emitted from the light-engine. A laser or SLED driver moduleis provided which can dynamically control the light engine based oninput from an external source. For example, the laser driver modulegenerates a drive current, with the drive currents being adapted todrive one or more laser diodes, based on one or more signals.

Optionally, the quality of the light emitted by the white light sourcemay be adjusted based on input from one or more sensors. Qualities ofthe light that can be adjusted in response to a signal include but arenot limited to: the total luminous flux of the light source, therelative fraction of long and short wavelength blue light as controlledby adjusting relative intensities of more than one blue laser sourcescharacterized by different center wavelengths and the color point of thewhite light source by adjusting the relative intensities of red andgreen laser sources. Such dynamic adjustments of light quality mayimprove productivity and health of workers by matching light quality towork conditions.

Optionally, the quality of the white light emitted by the white lightsource is adjusted based on input from sensors detecting the number ofindividuals in a room. Such sensors may include motion sensors such asinfra-red motion sensors, microphones, video cameras, radio-frequencyidentification (RFID) receivers monitoring RFID enabled badges onindividuals, among others.

Optionally, the color point of the spectrum emitted by the white lightsource is adjusted by dynamically adjusting the intensities of the blue“pump” laser sources relative to the intensities of the green and redsources. The total luminous flux of the light source and the relativeproportions are controlled by input from a chronometer, temperaturesensor and ambient light sensor measuring to adjust the color point tomatch the apparent color of the sun during daylight hours and to adjustthe brightness of the light source to compensate for changes in ambientlight intensity during daylight hours. The ambient light sensor wouldeither be configured by its position or orientation to measure inputpredominantly from windows, or it would measure ambient light duringshort periods when the light source output is reduced or halted, withthe measurement period being too short for human eyes to notice.

Optionally, the color point of the spectrum emitted by the white lightsource is adjusted by dynamically adjusting the intensities of the blue“pump” laser sources relative to the intensities of the green and redsources. The total luminous flux of the light source and the relativeproportions are controlled by input from a chronometer, temperaturesensor and ambient light sensor measuring to adjust the color point tocompensate for deficiencies in the ambient environmental lighting. Forexample, the white light source may automatically adjust total luminousflux to compensate for a reduction in ambient light from the sun due tocloudy skies. In another example, the white light source may add anexcess of blue light to the emitted spectrum to compensate for reducedsunlight on cloudy days. The ambient light sensor would either beconfigured by its position or orientation to measure input predominantlyfrom windows, or it would measure ambient light during short periodswhen the light source output is reduced or halted, with the measurementperiod being too short for human eyes to notice.

In a specific embodiment, the white light source contains a plurality ofblue laser devices emitting spectra with different center wavelengthsspanning a range from 420 nm to 470 nm. For example, the source maycontain three blue laser devices emitting at approximately 420, 440 and460 nm. In another example, the source may contain five blue laserdevices emitting at approximately 420, 440, 450, 460 and 470 nm. Thetotal luminous flux of the light source and the relative fraction oflong and short wavelength blue light is controlled by input from achronometer and ambient light sensor such that the emitted white lightspectra contains a larger fraction of intermediate wavelength blue lightbetween 440 and 470 nm during the morning or during overcast days inorder to promote a healthy circadian rhythm and promote a productivework environment. The ambient light sensor would either be configured byits position or orientation to measure input predominantly from windows,or it would measure ambient light during short periods when the lightsource output is reduced or halted, with the measurement period beingtoo short for human eyes to notice.

Optionally, the white light source would be provided with a VLC-receiversuch that a plurality of such white light sources could form a VLC meshnetwork. Such a network would enable the white light sources tobroadcast measurements from various sensors. In an example, a VLCmesh-network comprised of VLC-enabled white light sources could monitorambient light conditions using photo sensors and room occupancy usingmotion detectors throughout a workspace or building as well ascoordinate measurement of ambient light intensity such that adjacentlight sources do not interfere with these measurements. In an example,such fixtures could monitor local temperatures using temperature sensorssuch as RTDs and thermistors among others.

In an embodiment, the white light source is provided with acomputer-controlled video camera. The white light source contains aplurality of blue laser devices emitting spectra with different centerwavelengths spanning a range from 420 nm to 470 nm. For example, thewhite light source may contain three blue laser devices emitting atapproximately 420, 440 and 460 nm. In another example, the white lightsource may contain five blue laser devices emitting at approximately420, 440, 450, 460 and 470 nm. The total luminous flux of the whitelight source and the relative fraction of long and short wavelength bluelight is controlled by input from facial recognition and machinelearning based algorithms that are utilized by the computer control todetermine qualities of individuals occupying the room. In an example,number of occupants is measured. In another example, occupants may becategorized by type, sex, size, and color of clothing among otherdifferentiable physical features. In another example, mood and activitylevel of occupants may be quantified by the amount and types of motionof occupants.

FIG. 21A shows a functional block diagram for a basic laser-basedVLC-enabled laser light source or “light engine” that can function as awhite light source for general lighting and display applications andalso as a transmitter for visible light communication such as LiFi. Thisdiagram is merely an example, which should not unduly limit the scope ofthe claims. One of ordinary skill in the art would recognize manyvariations, alternatives, and modifications. Referring to FIG. 21A, thewhite light source includes three subsystems. The first subsystem is thelight emitter 1509, which consists of either a single laser device or aplurality of laser devices (1503, 1504, 1505 and 1506). The laserdevices are configured such that the laser light from each laser deviceis incident on a wavelength converting element 1507 such as a phosphorwhich absorbs part or the entirety of the laser light from one or morelaser devices and converts it into a broader spectrum of lower energyphotons. The second subsystem is the control unit 1510, which includesat least a laser driver 1502 and a VLC modem 1501. The laser driver 1502powers and modulates the all laser devices (1503, 1504, 1505 and 1506)to enable them for visible light communications. Optionally, the laserdriver 1502 at least can drive one laser device independently of therest. The VLC modem 1501 is configured to receive digitally encoded datafrom one or more data sources (wired or wirelessly) and convert thedigitally encoded data into analog signals which determine the output ofthe laser driver 1502. The modulation of the laser light by the laserdriver based on the encoded data can be either digital, with the emittedpower of the laser being varied between two or more discrete levels, orit can be based on the variation of the laser intensity with atime-varying pattern where data is encoded in the signal by way ofchanges in the amplitude, frequency, phase, phase-shift between two ormore sinusoidal variations that are summed together, and the like.

In an example, as used herein, the term “modem” refers to acommunication device. The device can also include a variety of otherdata receiving and transferring devices for wireless, wired, cable, oroptical communication links, and any combination thereof. In an example,the device can include a receiver with a transmitter, or a transceiver,with suitable filters, and analog front ends. In an example, the devicecan be coupled to a wireless network such as a meshed network, includingZigbee, Zeewave, and others. IN an example, the wireless network can bebased upon a 802.11 wireless standard or equivalents. In an example, thewireless device can also interface to telecommunication networks, suchas 3G, LTE, 5G, and others. In an example, the device can interface intoa physical layer such as Ethernet or others. The device can alsointerface with an optical communication including a laser coupled to adrive device, or a am amplifier. Of course, there can be othervariations, modifications, and alternatives.

In some preferred embodiments the output of the laser driver isconfigured for a digital signal. The third subsystem is an optional beamshaper 1508. The light emitted from the wavelength converting element1507 (which absorbed the incident laser light) as well as unabsorbed,scattered laser light passes through the beam shaper 1508 which directs,collimates, focuses or otherwise modifies the angular distribution ofthe light. After the beam shaper 1508 the light is formulated as acommunication signal to propagate either through free-space or via awaveguide such as an optical fiber. The light engine, i.e., thelaser-based white light source is provided as a VLC-enabled lightsource. Optionally, the beam shaper 1508 may be disposed prior to thelight incident to the wavelength converting element 1507. Optionally,alternate beam shapers are disposed at optical paths both before andafter the wavelength converting element 1507.

In some embodiments, additional beam shapers would be included betweenthe laser diode members and the wavelength converter element toprecondition the pump beam before it is incident on the phosphor. Forexample, in a preferred embodiment the laser or SLED emission would becollimated prior to incidence with the wavelength converter such thatthe laser light excitation spot would have a specified and controlledsize and location.

For a single laser-based VLC light source, this configuration offers theadvantage that white light can be created from combination of alaser-pumped phosphor and the residual, unconverted blue light from thelaser. When the laser is significantly scattered it will have aLambertian distribution similar to the light emitted by the wavelengthconverting element, such that the projected spot of light has uniformcolor over angle and position as well as power of delivered laser lightthat scales proportionally to the white light intensity. For wavelengthconverting elements that do not strongly scatter laser light, the beamshaping element can be configured such that the pump and down convertedare collected over similar areas and divergence angles resulting in aprojected spot of light with uniform color over angle, color overposition within the spot, as well as power of delivered laser light thatscales proportionally to the white light intensity. This embodiment isalso advantageous when implemented in a configuration provided withmultiple pump lasers in that it allows for the pump laser light from theplurality of lasers to be overlapped spatially on the wavelengthconverting element to form a spot of minimal size. This embodiment isalso advantageous in that all lasers can be used to pump the wavelengthconverting element-assuming the lasers provided emit at wavelengthswhich are effective at pumping the wavelength converting element-suchthat power required from any one laser is low and thus allowing foreither use of less-expensive lower-power lasers to achieve the sametotal white light output or allowing for under-driving of higher-powerlasers to improve system reliability and lifetime.

FIG. 21B shows another functional diagram for a basic laser-basedVLC-enabled light source for general lighting and display applicationsand also as a transmitter for visible light communication. This diagramis merely an example, which should not unduly limit the scope of theclaims. One of ordinary skill in the art would recognize manyvariations, alternatives, and modifications. Referring to FIG. 21B, thewhite light source includes three subsystems. The first subsystem is thelight emitter 1530, which consists of a wavelength converting element1527 and either a single laser device or a plurality of laser devices1523, 1524, 1525 and 1526. The laser devices are configured such thatthe laser light from a subset of the laser devices 1523 and 1524 ispartially or fully converted by the wavelength converting element 1527into a broader spectrum of lower energy photons. Another subset of thelaser devices 1525 and 1526 is not converted, though they may beincident on the wavelength converting element. The second subsystem isthe control unit 1520 including at least a laser driver 1522 and a VLCmodem 1521. The laser driver 1522 is configured to power and modulatethe laser devices. Optionally, the laser driver 1522 is configured todriver at least one laser device independently of the rest among theplurality of laser devices (e.g., 1523, 1524, 1525 and 1526). The VLCmodem 1521 is configured to couple (wired or wirelessly) with a digitaldata source and to convert digitally encoded data into analog signalswhich determine the output of the laser driver 1522. The third subsystemis an optional beam shaping optical element 1540. The light emitted fromthe wavelength converting element 1527 as well as unabsorbed, scatteredlaser light passes through the beam shaping optical element 1540 whichdirects, collimates, focuses or otherwise modifies the angulardistribution of the light into a formulated visible light signal.

In some embodiments, additional beam shapers would be included betweenthe laser diode members and the wavelength converter element toprecondition the pump light beam before it is incident on the phosphor.For example, in a preferred embodiment the laser or SLED emission wouldbe collimated prior to incidence with the wavelength converter such thatthe laser light excitation spot would have a specified and controlledsize and location. The light signal then leaves the light engine andpropagates either through free-space or via a waveguide such as anoptical fiber. In an embodiment, the non-converted laser light isincident on the wavelength converting element 1527, however thenon-converted laser light is efficiently scattered or reflected by thewavelength converting element 1527 such that less than 10% of theincident light is lost to absorption by the wavelength convertingelement 1527.

This embodiment has the advantage that one or more of the datatransmitting lasers is not converted by the wavelength convertingelement. This could be because the one or more lasers are configuredsuch that they are not incident on the element or because the lasers donot emit at a wavelength that is efficiently converted by the wavelengthconverting element. In some examples, the non-converted light might becyan, green or red in color and may be used to improve the colorrendering index of the white light spectrum while still providing achannel for the transmission of data. Because the light from theselasers is not converted by the wavelength converting element, lowerpower lasers can be used, which allows for lower device costs as well asenabling single lateral optical mode devices which have even narrowerspectra than multi-mode lasers. Narrower laser spectra would allow formore efficient wavelength-division multiplexing in VLC light sources.

Another advantage is that the lasers that bypass the wavelengthconverting element may be configured to allow for highly saturatedspectra to be emitted from the VLC capable light source. For example,depending on the wavelength converting element material andconfiguration, it may not be possible to have a blue laser incident onthe wavelength converting element that is not partially converted tolonger wavelength light. This means that it would be impossible to usesuch a source to produce a highly saturated blue spectrum as there wouldalways be a significant component of the emitted spectrum consisting oflonger wavelength light. By having an additional blue laser source,which is not incident on the wavelength converting element, such asource could emit both a white light spectrum as well as a saturatedblue spectrum. Addition of green and red emitting lasers would allow thelight source to emit a white light spectrum by down conversion of a blueor violet pump laser as well as saturated, color-tunable spectra able toproduce multiple spectra with color points ranging over a wide area ofthe color gamut.

FIG. 22A is a functional block diagram for a laser-based smart-lightingsystem according to some embodiments of the present invention. Thisdiagram is merely an example, which should not unduly limit the scope ofthe claims. One of ordinary skill in the art would recognize manyvariations, alternatives, and modifications. As shown, thesmarting-lighting system includes a laser-based dynamic white lightsource including a blue laser device 2005 emitting a spectrum with acenter wavelength in the range of 380-480 nm. The system includes anoptional beam shaping optical element 2006 provided for collimating,focusing or otherwise shaping the beam emitted by the laser device 2005.The laser light from the laser device 2005 is incident onto a wavelengthconverting element 2007. The system additionally includes an element2008 for shaping and steering the white light out of the wavelengthconverting element 2007. One or more sensors, Sensor1 2002, Sensor22002, up to SensorN 2004, are provided with the digital or analog outputof the sensor being received by the laser driver 2001 and a mechanismprovided whereby the laser driver output is modulated by the input fromthe sensors.

FIG. 22B is a functional diagram for a dynamic, laser-basedsmart-lighting system according to some embodiments of the presentinvention. This diagram is merely an example, which should not undulylimit the scope of the claims. One of ordinary skill in the art wouldrecognize many variations, alternatives, and modifications. As shown,one or more laser devices 2106 are provided along with beam shapingoptical elements 2107. The laser devices 2106 and beam shaping opticalelements 2107 are configured such that the laser light is incident on awavelength converting element 2108 that absorbs part or all laser lightand emits a longer wavelength spectrum of light. Beam shaping andsteering elements 2110 are provided which collect light from thewavelength converting element 2008 along with remaining laser light anddirect it out of the light source. The light source is provided with alaser driver 2005 that provides controlled current and voltage to theone or more laser devices 2006. The output of the laser driver 2105 isdetermined by the digital or analog output of a microcontroller (orother digital or analog control circuit) 2101. The light source is alsoprovided with a steering element driver 2109 which controls the beamsteering optical element 2110. The output of the steering element driver2109 is determined by input from the control circuit. One or moresensors 2102, 2103 and 2104 are provided. A digital or analog output ofthe sensors is read by the microcontroller 2101 and then converted intoa predetermined change or modulation of the output from the controlcircuit to the laser driver 2105 and steering element driver 2109 suchthat the output of the light source is dynamically controlled by theoutput of the sensors.

In some embodiments, the beam steering optical elements include ascanning mirror. In an example, among the one or more laser devices, atleast one laser device emits a spectrum with a center wavelength in therange of 380-480 nm and acts as a violet or blue light source. The bluerange of wavelengths illuminates the wavelength converting element whichabsorbs part of the pump light and reemits a broader spectrum of longerwavelength light. Both light from the wavelength converting element andthe one or more laser devices are emitted as a white light. Optionally,a laser or SLED driver module is provided for dynamically controllingthe one or more laser devices based on input from an external source toform a dynamic light source. For example, the laser driver modulegenerates a drive current, with the drive current being adapted to driveone or more laser diodes, based on one or more signals. The dynamiclight source has a scanning mirror and other optical elements for beamsteering which collect the emitted white light spectrum, direct themtowards the scanning mirror and either collimate or focus the light. Ascanning mirror driver is provided which can dynamically control thescanning mirror based on input from an external source. For example, thescanning mirror driver generates either a drive current or a drivevoltage, with the drive current or drive voltage adapted to drive thescanning mirror to a specific orientation or through a specific range ofmotion, based on one or more signals.

FIG. 23A shows a schematic diagram of an apparatus comprising both adepth sensing system and laser based visible light source according tosome embodiments of this invention. This diagram is merely an example,which should not unduly limit the scope of the claims. One of ordinaryskill in the art would recognize many variations, alternatives, andmodifications. In general, this apparatus is a portable lighting devicefor depth sensing or range finding or LIDAR. Here it is referred as adepth sensing system for simplification only. Optionally, the portablelighting device can be configured to be a lighting device such asflashlight, spotlight, outdoor security light for recreation, defense,security, search, and rescue etc. As shown, the apparatus 2800 such as amobile machine is comprised of at least one power source 2801 thatserves as the energy source for both the laser light illumination system2810 and the depth sensing system 2820. The laser light illuminationsystem 2810 is comprised of a gallium and nitrogen containing laserdiode 2811 operating with a first electromagnetic radiation output inthe blue wavelength region (420 to 485 nm) or the violet wavelengthregion (390 to 420 nm). The first output electromagnetic radiation is anincident beam onto a wavelength conversion member such as a phosphormaterial where at least a fraction of the first blue or violet peakwavelength is converted to a second peak wavelength to generate a whitelight as an output beam with a mixed first peak wavelength and thesecond peak wavelength. In some preferred embodiments the wavelengthconversion member or phosphor material is operated in a reflection modeto produce the output beam relative to the incident beam. In otherpreferred embodiments the wavelength conversion member or phosphormaterial is operated in a transmission mode to produce the output beamrelative to the incident beam. Once the white light is generated it iscoupled through an optical member such as a collimating optic to shapethe output beam.

The depth sensing system 2820 is comprised of a laser subsystem havingat least a transmitter module 2822 containing a laser, wherein thetransmitter 2822 is configured to generate and direct laser light pulsesas one or more sensing light signals to the surrounding environment. Thedepth sensing system 2820 also includes a detection subsystem includingat least a receiver module 2823, which functions to detect light signalsupon returns of the one or more sensing light signals after reflectionoff the surrounding environment. Further the depth sensing system 2820includes a processer 2821 to synchronize the transmitter 2822 andreceiver 2823, process both the transmitted laser light pulses andreflected light signals, and perform time-of-flight calculations todetermine the distances to all surrounding objects and generate a3-dimensional map thereof.

The laser light illumination system 2810 can optionally be coupled tothe depth sensing system 2820 through a signal processor and/orgenerator 2802 that is configured to control the laser lightillumination system based on feedback or information provided from thedepth sensing system 2820. In one example the depth sensing system 2820detects an oncoming mobile object. To prevent glare to the oncomingobject the processing unit 2802 adjusts the current to the laser lightillumination system 2810 to dim or reduce the brightness of the laserlight illumination system 2810 to prevent glare hazards. In analternative example, the depth sensing system 2820 detects a movingobject that the operator of the mobile machine may not be aware of andcould prevent a safety hazard such as a collision hazard. In this casethe processing unit 2802 generates a signal to the laser lightillumination system 2810 to modify the light characteristic such asactivating a spotlight function on the moving object to bring it to theoperator's attention. Additionally, the laser light illumination system2810 could be a dynamic source with the ability to dynamically changethe beam angle and/or the spatial pattern/location of the light outputsuch that the moving object can be dynamically tracked with a spotlight.

In one example of the present embodiment, components of the laser-basedlighting system 2810 and the depth sensing system 2820 could be housedwithin a common package as an integrated system 2800 or as separatesystems. For example, the depth sensing system 2820 and laser-basedlighting system 2810 could be housed within the headlamp of anautomobile such as an autonomous vehicle. In another example thelaser-based lighting system and depth sensing system could be containedin the lighting housing on a drone.

In one example, a laser based lighting system and a depth sensing systemare provided on a mobile machine such as an autonomous vehicle or dronewherein the LIDAR system is used for scanning and navigation and thelaser based lighting system is used for spotlighting objects or terrainto provide a communication or warning. In one preferred embodiment, thedepth sensing function and illumination function are connected via aloop wherein the depth sensing result is acting as a sensor signal tofeedback into dynamic laser-based illumination pattern. For example, ifa range mapping is detected an animal on the side of the road, the laserillumination source could be configured to preferentially spotlight it.In another example, if an oncoming car is detected by the range mappingthe laser-based illumination pattern can be configured to blank out ordarken the beam on the oncoming traffic. Of course, there are manyexamples of how a dynamic illumination pattern and a dynamic depthscanning pattern can be used in conjunction for added functionality andsafety in many applications including automotive, recreation,commercial, space and defense, etc.

FIG. 23B is a simplified schematic diagram of a laser light illuminationsystem integrated with a depth sensing system according to someembodiments of the present invention. This diagram is merely an example,which should not unduly limit the scope of the claims. One of ordinaryskill in the art would recognize many variations, alternatives, andmodifications. In general, this apparatus is a portable lighting devicefor depth sensing or range finding or LIDAR. Optionally, the portablelighting device can be configured to be a lighting device such asflashlight, spotlight, outdoor security light for recreation, defense,security, search, and rescue etc. As shown in the figure, the integratedsystem 2900 is configured with a power source 2901 to supply power toboth the depth sensing system and the laser light illumination system.Optionally, separate or multiple power supplies 2901 could be used alongwith a controller 2902 including a processor and some drive electronicsconfigured to receive power from the power supply 2901 and receive dataor signals from receiver components 2931 of the depth sensing system.Based on external inputs 2990 such as user inputs or predeterminedinputs to provide specified functionality and power supplied from thepower supply 2901, the controller 2902 determines appropriate drivesignals being sent to one or more gallium and nitrogen containing laserdiodes 2903. The drive signal is configured to drive the current andvoltage characteristic of the laser diode 2903 to generate anappropriate intensity pattern from the laser diode to provide a firstelectromagnetic radiation characterized with a first peak wavelengthsuch as a blue or violet peak wavelength. In one embodiment the drivesignal is configured to generate both the appropriate pattern of laserlight required in the laser illumination source with the desiredbrightness and luminous flux along with the laser emission for the depthsensing scan function with the desired sensing light signal or laserpulse for the depth sensing system to sense reflected light signal basedon the sensing light signal and perform time-of-flight calculation basedon both the sensing light signal and the reflected light signal. In analternative embodiment an optical modulator could be included toseparately encode a signal on the light for the depth sensing system orfor the laser light illumination source.

As shown in the FIG. 23B, the first electromagnetic radiation at thefirst peak wavelength from the laser diode 2903 is then split into twoseparate optical paths. The first optical path is incident on awavelength conversion member 2911 (e.g., a phosphor) where at least afraction of the first electromagnetic radiation with the first peakwavelength is converted to a second electromagnetic radiation (emissionfrom the excited phosphor) with a second peak wavelength. Optionally,the second peak wavelength is in yellow color range. In a preferredembodiment, the second electromagnetic radiation is mixed with a partialportion of the first electromagnetic radiation to produce an outputelectromagnetic radiation of the laser-based illumination system as awhite light. The resulting output electromagnetic radiation is thenconditioned with one or more beam shaping elements 2912 to provide apredetermined collimation, divergence, and pattern. Optionally, a beamsteering element can be added to the laser-based illumination system tocreate a spatially dynamic illumination. In some embodiments anadditional beam shaping element such as a collimating optic is used tocollimate the laser light prior to incidence on the wavelengthconversion member 2911. Additionally, optical fibers such as glass orpolymer fibers or other waveguide elements can be used to transport thelaser light from the laser diode 2903 to the wavelength conversionmember 2911 to create a remotely pumper conversion.

According to FIG. 23B, the second optical path directs theelectromagnetic radiation with the first peak wavelength to the depthsensing transmitter module 2921 where it can be combined with othertransmitter components. In some embodiments a collimating optic such asa lens is used to collimate the laser light prior to entry in thetransmitter module 2921 of the depth sensing system. Additionally,optical fibers such as glass or polymer fibers or other waveguideelements can be used to transport the laser light from the laser diode2903 to the depth sensing transmitter module 2921. As describedpreviously, an optical modulator could be included within this secondoptical path to generate an optical pulse or other optical signal as asensing light signal required for the desired depth sensing function.Before exiting to the outside environment, the sensing light signal ofthe LIDAR system can be properly conditioned by transmission optics 2922for depth sensing system with the appropriate divergence and directionto scan the sensing light signal over the desired target area of thesurrounding environment. A map of the desired target area can becaptured by the depth sensing system in various ways including scanningthe sensing light signal using a dynamic scanner such as a MEMS scanningmirror, recording image using a microdisplay such as a DLP, or LCOS,and/or simply expanding or shaping the beam using basic optics 2932 suchas lens, mirrors, and diffusing elements. Once all of the signalprocessing and beam conditioning are completed by the transmissionoptics 2922, the depth sensing light beam is projected externally to thetarget area where it reflects and scatters off of the various remotetarget objects in the surrounding environment and fractionally returnsto the receiver module 2931 of the depth sensing system. The receivermodule 2931 is comprised of some receiver optical components and asignal processor (such as analog-to-digital converter), a detectionmember 2932 such as a photodiode, a photodiode array, a CCD array, anantenna array, a scanning mirror or microdisplay coupled to a photodiodeor other configured to detect reflected or scattered light signals fromthe remote target object and convert them to electrical signals. Theelectrical signals detected by the detection member 2932 are received bythe receiver module 2931 and then used to calculate a time of flight forthe transmitted and detected depth sensing signal such as a sensinglight beam. Optionally, a spatial map of the remote target object can begenerated by the signal processor associated with the receiver module2931. The calculations or processing to determine the time of flight andthe spatial map can be done directly in the receiver 2931.Alternatively, the spatial map generation is done in the separateprocessor unit 2902.

Of course there are many novel configurations of this embodiment can berealized. For example, the light source of the laser-based illuminationsystem could be comprised of multiple gallium and nitrogen containinglaser diodes wherein one or more of the multiple laser diodes are usedfor the depth sensing scan function. In an example, the multiple galliumand nitrogen containing laser diodes operating in a range of 390 nm to550 nm are used in the depth sensing system for multi-wavelength(multi-spectral) or hyper-spectral depth sensing illumination scanning.Such wavelength diversity coupled with corresponding signal conditioningand detection can allow increased sensitivity and/or provide the depthsensing user with more information regarding the environmentallandscape. In alternative embodiments other wavelength ranges could begenerated from the gallium and nitrogen containing laser diodes such asultra-violet, cyan, green, yellow, orange, or red. Additionally, anynumber of scanning, rastering, or imagine generating technologies can beincluded such as DLP, LCOS, and scanning fiber.

In an alternative embodiment, a laser based lighting system wherein thegallium and nitrogen containing laser diode wavelength is used for depthsensing illumination is configured within a conventional depth sensingsystem making use of standard depth sensing wavelengths such as 905 nm,1000 nm, 1064 nm, 1550 nm, or other. By combining the wavelengths suchas a blue wavelength from a range of 390 nm to 480 nm from the galliumand nitrogen containing laser diode with an infrared wavelength from aconventional depth sensing system can have an increased sensitivity orfunctionality. This increased sensitivity and functionality is achievedby using the separate wavelengths to sense different characteristics ofthe environment based or based on differential analysis in the returnsignals or echoes such as the amplitude, time of flight, or phase. Insome embodiments, no gallium and nitrogen containing laser diodesemitting at longer wavelength are used in the system including GaAs orInP based laser diodes.

In another embodiment, the laser light excitation beam that has beenreflected and/or scattered from the wavelength conversion member in thelaser light illumination system can be used for realizing the depthsensing sensing function. In the embodiment, a beam splitter or similarcomponent is eliminated to “pick off” a part of the direct laser beamfor depth sensing prior to exciting the wavelength converter member. Forexample, a violet to blue laser with a first wavelength in the range of390 nm to 480 nm from a GaN-based laser diode excites a wavelengthconversion member such as a phosphor to generate a longer secondwavelength emission. In one example the second wavelength is ayellow-color emission that mixes with the remaining violet or blue-coloremission from the GaN-based laser diode to make a white light emission.This white light emission, which could have a Lambertian pattern, isthen collimated and coupled to a 1 or 2-dimensional scanner such as ascanning MEMS mirror. The scanning member of the scanner would thensweep the collimated beam of light amongst the environment andsurroundings and serve as a depth sensing scan illumination member. Theviolet or blue first wavelength within the collimated white light beamsweeps across the environment and senses the returned(scatter/reflected) laser beam to calculate the distances from thescattering objects using a time of flight method, and hence generating a3-dimensional map. The violet or blue laser provided for depth sensingis characterized by high power levels in one range selected from 1 mW 10mW, 10 mW to 100 mW, 100 mW to 1 W, and 1 W to 10 W capable of sensingand mapping the remote target object under damp condition with relativehumidity level in each of following ranges of greater than 25%, greaterthan 50%, greater than 75%, and greater than 100%.

In a common configuration of this embodiment the laser source and/orscanning member would be operated to generate a periodic short pulse oflight or a modulated intensity scheme to enable synchronization of thetransmitted and detected signal. The detector could be configured with anotch-pass filter designed to accept wavelengths only within a narrowband (i.e., 2-20 nm or 20-100 nm) centered around the laser emissionwavelength such as the violet or blue wavelength in the excitationsource. Such a configuration would lend itself optimally to a spatiallydynamic laser-based light embodiments described throughout thisinvention that combines a microdisplay such as a MEMS scanning mirrorwith the laser-based lighting/illumination technology. Further, smartlaser-based lighting systems would offer sensor feedback for closedfeedback loops enabling the depth sensing and smart laser lightingfunctions to activate and respond to changes in environmentalconditions.

FIG. 23C is a simplified schematic diagram of an apparatus having alaser light illumination system integrated with a depth sensing systemaccording to some alternative embodiments of the present invention. Thisdiagram is merely an example, which should not unduly limit the scope ofthe claims. One of ordinary skill in the art would recognize manyvariations, alternatives, and modifications. In general, this apparatusis a portable lighting device for depth sensing or range finding orLIDAR. Optionally, the apparatus can be configured as flashlight,spotlight, outdoor security light for recreation, defense, security,search, and rescue etc. As shown in the figure, the apparatus 3000 isconfigured with a power source 3001 to supply power to both thedepth-sensing system and an illumination system along with a processorand control unit 3002 configured to receive power from the power supply3001 and data or signals from the receiver portion 3031 of thedepth-sensing system. Based on external inputs 3090 such as user inputsor predetermined inputs to provide specified functionality and powersupplied from the power supply 3001, the processor and control unit 3002determines the appropriate driving signals based on the external inputs3090 to drive one or more laser diodes 3003 including gallium andnitrogen containing blue laser diodes and IR-emitting laser diodes. Thedriving signals are configured to determine current and voltagecharacteristics of the laser diodes 3003 to generate the appropriateintensity patterns provided as electromagnetic radiation with a firstpeak wavelength such as a blue or violet or infrared peak wavelength. Inone embodiment the driving signals are configured to generate both theappropriate patterns of laser light required in the laser illuminationsource with the desired brightness and luminous flux along with thelaser emission for the depth-sensing scanning function with the desiredsignal or laser pulse for depth sensing and time-of-flight calculation.In an alternative embodiment, an optical modulator is included toseparately encode a signal on the light for the depth-sensing system orfor the light illumination source.

As shown in the FIG. 23C, a primary electromagnetic radiation at thefirst peak wavelength from the laser diodes 3003 is directed as anincident light into a wavelength conversion member 3004. Optionally, thewavelength conversion member 3004 is a phosphor material which isexcited to reemit light with a longer wavelength by the incident lightof a certain wavelength. Thus, at least a fraction of the primaryelectromagnetic radiation with the first peak wavelength is converted toa secondary electromagnetic emission with a second peak wavelength, suchas a yellow peak wavelength. Optionally, a secondary electromagneticemission with a second peak wavelength is combined or mixed by one ormore beam shaping elements 3005 with at least a fraction of theelectromagnetic radiation with the first peak wavelength to produce awhite light. Optionally, the white light as the combined emissionincludes at least a first peak wavelength in violet or blue range and asecond peak wavelength in yellow range. Optionally, an infrared lightemission including a third peak wavelength in Infrared wavelength rangeis provided separately. Additionally, the one or more beam shapingelements 3005 is configured to provide a predetermined collimation,divergence, and pattern for guiding the combined white light emissionsor separately infrared light emission for both visible/IR illuminationand depth sensing.

As seen in the FIG. 23C, at least a portion of the combined emission isoutputted and shaped as a depth-sensing scanning emission. In anembodiment, the depth-sensing scanning emission generated by the one ormore beam shaping elements 3005 includes a first sensing light signalwith the first peak wavelength and a second sensing light signal withthe second peak wavelength based on the received laser-based whitelight, or a third sensing light with the third peak wavelength inInfrared range. On the one hand, the depth-sensing scanning emissioncould be fed through a depth sensing transmission components 3021 forsignal shaping, filtering, wavelength-dependent transmitting, beamsteering (which could be active beam steering with a MEMS or other),etc. before a beam of the first sensing light signal and the secondsensing light signal is projected via a depth-sensing signaltransmission module 3022 into the environment for scanning over a remotearea including the target objects and their surroundings. On the otherhand, a remaining portion of the combined visible or IR emission isprovided as a beam for illumination. The beam for illumination could befurther processed by additional beam shaping optical components 3011 tocollimate to 15 degrees or less as a better illumination source fortarget objects with enhanced directionality and reduced attenuation.Optionally, a beam steering element 3012 is additionally included tomanipulate the beam of the illumination source to create a spatiallydynamic illumination of at least part of the target objects.

In some embodiments, an additional beam shaping element such as acollimator is used to collimate the laser light prior to incidence onthe wavelength conversion member 3004. Additionally, optical fibers suchas glass or polymer fibers or other waveguide elements can be used totransport the laser light from the laser diodes 3003 to the wavelengthconversion member 3004 to create a remotely pumper conversion.

In an alternative embodiment, the white light outputted from the one ormore beam shaping elements 3005 as a combined emission of a primaryemission from the laser diode and a secondary emission from thewavelength conversion member 3004 are split into two optical pathwaysfor separate conditioning and steering possibilities respectively with afirst beam for the illumination system and a second beam for thedepth-sensing system. In other embodiments, the depth-sensing system andthe laser illumination system may follow the same optical pathway suchthat the illumination area and the 3D scanned area from thedepth-sensing system are nearly the same.

In another alternative embodiment, the white light outputted from theone or more beam shaping elements 3005 is fed through a single opticalpathway to a beam projector that includes the depth-sensing transmissioncomponents 3021, the depth-sensing signal transmission module 3022, thebeam shaping optical components 3011, and the beam steering element 3012for accomplishing multiple tasks of signal processing, filtering, beamshaping, collimating, projecting, amplifying, steering, scanning,modulating to generate the first sensing light signal with the firstpeak wavelength, the second sensing light signal with the second peakwavelength, and optionally the third sensing light signal with the thirdpeak wavelength and the beam of white light and/or infrared light forillumination. Alternatively, the beam projector may contain a hybridcollimator to handle the combined emission. The hybrid collimatorincludes a center collimator configured to collimate a portion of thewhite light or IR light as a depth sensing light beam and an outercollimator configured to collimate a remaining portion of the whitelight or IR light as an illumination beam. In particular, the portion ofthe white light or IR light collimated as a depth sensing light beamincludes a first sensing light signal with the first peak wavelengthfrom primary laser diode 3003, a second sensing light signal with thesecond peak wavelength from the secondary emission of the wavelengthconversion member 3004, and a third sensing light signal with the thirdpeak wavelength in Infrared range provided from IR-emitting laser diode.The center collimator is configured to collimate beams of the firstsensing light signal, the second sensing light signal, and/or the thirdsensing light signal to less than 1 or 2 degrees which is preferred fordepth sensing light scanning and return light detection with a highlydirectional beam over one or more target objects and surroundingenvironment. The outer collimator is configured to collimate a beam ofthe white light or IR light to less than 15 degrees for simplyilluminating the one or more target objects.

As described previously, the laser light illumination system integratedwith a depth-sensing system includes an optical modulator configured togenerate a pulse signal required for the desired depth sensing function.The target depth-sensing or range mapping area can be captured invarious ways by scanning the depth sensing light signals via opticsincluding a dynamic scanner such as a MEMS scanning mirror, amicrodisplay such as a DLP, or by simply expanding or shaping the highlycollimated beam using basic optics such as lens, mirrors, and diffusingelements. The optical modulator is configured to provide a modulationsignal with a first rate to drive the gallium and nitrogen containinglaser diode to emit the first light with a first peak wavelength whichis interrupted with a second rate, wherein the second rate issubstantially synchronized with a delayed modulation rate of the secondlight of yellow color reemitted from the wavelength conversion member.The delayed modulation rate associated with the yellow pulse from thewavelength conversion member is correlated to the rate of excitationblue pulses from the laser diode. Under slow modulation rates the pulsesmay be more or less synchronized and this may not be an issue. But underfast modulation rate, e.g., GHz, there will be hundreds to thousands ofblue pulses underneath one yellow pulse. The secondary yellow emissionwill look like background noise as it will essentially not turn-off.This could be overcome by including pulse interruptions in theexcitation signal. These interruptions would set the bit length for theyellow color signal.

Once all of the signal transmission and beam conditioning is completed,a collimated depth sensing light beam including both the first sensinglight signal and the second sensing light signal for the depth sensingsystem is projected externally to a designed projection area includingvarious target objects and the surrounding environment. Optionally, thedepth sensing light beam is provided in each scanning cycle as a seriesof light pulses having at least the first peak wavelength and the secondpeak wavelength. The first sensing light signal and the second sensinglight signal are respectively reflected and scattered off the varioustarget objects in the projection area. At least a fraction of thereflected/scattered light signal is received by a receiver module 3031of the depth-sensing system. The receiver module 3031 is coupled to someoptical receiving components 3032 including one or more opticaldetectors such as a photodiode, a photodiode array, a CCD array, anantenna array, a scanning mirror or microdisplay coupled to a photodiodeor other to detect the reflected/scattered light signal and convert itto electrical signal. The receiver module 3031 further includes at leasta signal processor to process the electrical signal into digital formatand further to calculate a time of flight based on both the transmittedsecond sensing light signal and the detected signal in digital format.The time of flight information can be used to generate a spatial map orimage of the target objects and their surroundings.

Optionally, the receiver module 3031 includes a first signal receiverconfigured to detect reflected signals of the first sensing light signalto generate a first image of the one or more target objects, a secondsignal receiver configured to detect reflected signals of the secondsensing light signal to generate a second image of the one or moretarget objects. Optionally, the first image generated by the firstsignal receiver is synchronized with the second image generated by thesecond signal receiver to obtain a color-differential image of the oneor more target objects. The difference in attenuation between blue colorlight and yellow color light can provide information about theenvironment including the air or other space the light signals aretraveling through or the materials the light signals are reflectingfrom. Similarly, the difference in return-time for the blue color andyellow color signal light can provide information about the material thelight is traveling through due to dispersion. Optionally, thecalculations or processing to determine the time of flight and thespatial map or image of the target object/area can be done directly inthe receiver module 3031 or alternatively in the processor and controlunit 3002.

It is to be appreciated that extremely high luminance is achieved forthe laser based light sources outputted from a wavelength conversionmember (3004 such as phosphor) to be used in the depth-sensing or LIDARapplications. Lasers by themselves are typically used in depth sensingsystems largely due to the characteristics of high directionality, lowattenuation, and extreme luminance. The emission characteristics enablethe laser light to be highly collimated to maintain a controlled beam toaccurately and densely survey the environment over large distances (i.e.10 m to 10,000 m). Other illumination sources such as LEDs are simplynot capable of meet such luminance requirements to enable thecollimation and directionality. However, advanced laser based lightingsystems using high power lasers to illuminate tiny spots on phosphorsand generate 300 to 3,000 lumens of light from a spot size (opticalaperture) of 50 μm to 1000 μm can enable extreme collimation even thoughthe emission from the phosphor (i.e., wavelength conversion member) maybe Lambertian. Thus, in such a laser-based lighting system the opticalbeam can be collimated to less than 1 degree, less than 2 degrees, orless than 5 degrees to enable the directionality and intensity requiredin depth-sensing or LIDAR applications. In some examples of all theembodiments described herein, certain and separate optics may be usedfor the depth-sensing system compared to the lighting or illuminationsystem. For example, a hybrid optical beam collimator could be used toenable a center beam collimation that is separated from the outer beamcollimation. The center beam collimation may be a higher collimationsuch as less than 1 or 2 degrees to serve as the primary depth-sensingtransmission beam collimator. The outer beam collimation may be a lowercollimation such as less than 15 degrees, less than 10 degrees, or lessthan 5 degrees and serve as the primary illumination beam collimator. Ofcourse, this is just merely one example of how the optical system couldbe designed to separately optimize the depth-sensing transmission beamof light from the lighting system lighting characteristics.

The benefits of the present example are many folds. As mentioned above,integration of depth-sensing systems with laser based smart lightingsystems making use of micro-displays is a nice additional benefit of thesmart light configuration that already requires a laser source and ascanning system. In this configuration the dynamic laser based lightsource is being used both for the lighting function and thedepth-sensing or LIDAR function. By combining the depth-sensing andlaser lighting function such as smart lighting into a common device,increased functionality, reduced cost, reduced size, and improvedreliability can be achieved. These benefits are critically important inseveral advanced technology applications such as autonomous vehicles,aircraft, and marine craft, along with military, defense, automotive,commercial, and specialty application where size, weight, and stylingare key design parameters, and cost is always important.

A key differentiation and benefit to the depth-sensing or LIDAR systemdescribed in these embodiments that employ one or more visible galliumand nitrogen containing laser diodes is the reduced absorption in watercompared to the more common infrared wavelengths used in depth sensing.As a result, under certain conditions these visible wavelengths willpass though moisture such as fog, rain, or bodies of water more freelythan the infrared (IR) wavelengths allowing increased depth sensingsensitivity in operating environments containing water. Thus, eventhough some scattering phenomena go as the inverse 4th power ofwavelength, water absorption is dramatically lower in the visible thanthe IR, resulting in higher efficiency performance in conditions wherethey may be water present, such as fog or rain. For example, using lightat 450 nm compare to 905 nm, scattering increases by 16×, such that 6%of the light transmits. However, the water absorption at 905 nm is morethan 100× that in the blue at 450 nm, resulting in more than 5 timeshigher signal. In one example, the blue wavelength from the laserexcitation source provides improved visibility and safety for anautonomous vehicle operating in moist or wet conditions. The improvedvisibility in the damp conditions could enhance safety for the vehicleand passengers within the vehicle.

FIG. 23D is a simplified schematic diagram of an apparatus having acombination of GaN containing laser and IR-emitting laser illuminationsystem integrated with a depth sensing system according to anotheralternative embodiment of the present invention. This diagram is merelyan example, which should not unduly limit the scope of the claims. Oneof ordinary skill in the art would recognize many variations,alternatives, and modifications. In general, this apparatus is aportable lighting device for depth sensing or range finding or LIDARapplication. Optionally, the apparatus can be configured as flashlight,spotlight, outdoor security light for recreation, defense, security,search, and rescue etc. As shown in the figure, the apparatus 3100 isconfigured with an internal power source 3101 to supply power to boththe laser-based illumination system and a depth sensing system.Optionally, the internal power supply 3101 is a chargeable power sourcewhich can receive charged electrical power from external inputs 3190.For example, the external inputs 3190 include a charging port.Optionally, the internal power supply 3101 is a chargeable battery andthe charging port is a USB-C port. In the embodiment, the apparatus 3100includes a control unit 3102 including processor and drive electronicsconfigured to receive power from the internal power supply 3101. Thecontrol unit 3102 is coupled to a GaN containing laser diode and anIR-emitting laser diode 3103, a wavelength converting member 3104, abeam shaping optics 3105, and optics 3110 for projecting visible/IRlight depth sensing signal to support the visible/IR light illuminationsystem of the apparatus 3100. At the same time, the control unit 3102 iscoupled with the optics 3110 for projecting and receiving visible/IRlight depth sensing signal to support the depth sensing system of theapparatus 3100.

Based on the external inputs 3190 the control unit 3102 determines theappropriate driving signals to drive one or more GaN containing laserdiodes and/or IR-emitting laser diode 3103. Optionally, the drivingsignals are configured to determine current and voltage characteristicsof each of the laser diodes 3103 to generate pulses of certainfrequencies in the emitted laser light. For GaN containing laser diode,the laser emission has a first peak wavelength in a blue or violetspectrum range. For the IR-emitting laser diode, the laser emission hasa third peak wavelength in infrared spectrum range. In one embodiment,the driving signals are configured to generate both spatially modulatedlaser pulses or timely modulated laser pulses with the desiredbrightness and luminous flux. The pulsed laser light is set a basis forgenerating depth sensing signals for performing scanning function andtime-of-flight calculation. In an alternative embodiment, an opticalmodulator is included in the control unit 3102 to separately encode apulsed laser signal for the depth-sensing system or aspatially-modulated light for the light illumination system.

As shown in the FIG. 23D, a primary electromagnetic radiation at thefirst peak wavelength from the GaN containing laser diode 3103 isdirected as an incident light into a wavelength conversion member 3104.Optionally, the wavelength conversion member 3104 is a phosphor materialwhich is excited to reemit light with a second wavelength longer thanthe first peak wavelength. Thus, at least a fraction of the primaryelectromagnetic radiation with the first peak wavelength is converted toa secondary electromagnetic emission with a second peak wavelength. Forexample, the first peak wavelength is a blue wavelength and the secondwavelength is a yellow wavelength. Optionally, the secondaryelectromagnetic emission with the second peak wavelength is combined ormixed by the wavelength converting member 3104 to produce a white light.In addition, a primary electromagnetic radiation at the third peakwavelength from the IR-emitting laser diode 3103 is also directed as anincident IR emission into the wavelength conversion member 3104. Thewavelength conversion member 3104 includes a phosphor material that isconfigured to primarily pass and reemit the IR emission substantiallywith little absorption. Either one of the white light or the IR emissionforms a beam outputted from the wavelength converting member 3104.Optionally, the beam carries the pulsed signals generated in the primaryelectromagnetic radiation with the first wavelength in blue or violetrange or the third wavelength in infrared range.

In the embodiment, the apparatus 3100 includes a beam shaping optics3105 configured with one or more beam shaping elements to collimate thelaser light out of the laser diodes to the wavelength converting member3104. Additionally, the beam shaping optics 3105 includes one or morebeam shaping elements configured to provide a predetermined collimation,divergence, and pattern for guiding a light beam combining white lightemission and/or infrared light emission ready for both visible/IRillumination and depth sensing. Optionally, one or more additional beamshaping elements receive a scattered beam of white light or IR emissionfrom the wavelength converting member 3104 and form a collimated beam ofthe white light emission or the beam of IR emission carrying the pulsedsignals. Optionally, a beam of the white light emission or a beam of IRemission is separately guided by the beam shaping optics 3105.Optionally, a combined beam with mixed white-color and infrared light isshaped for visible/IR light illumination and for depth sensing based onthe pulsed signals carried therein.

In an embodiment, the beam of white-color light and/or infrared lightgenerated by the beam shaping optics 3105 is provided within theapparatus 3100 to the optics 3110 for projecting the beam ofwhite-color/IR light carrying pulsed signal for depth sensing. On theone hand, the optics 3110 includes one or more optical transmit elementsconfigured to perform beam steering functions including scanning,focusing, deflecting, amplifying, projecting, and transmitting to guideat least a portion of the beam of white-color/IR light as a directionaldepth-sensing signal towards any target of interest in the field.Optionally, the optics for steering visible light beam is separate fromoptics for illuminating IR light beam. Optionally, either one or boththe visible light beam and the IR light beam carries pulsed depthsensing signal to produce a single or double spectrum depth sensingdetection. The apparatus 3100 is configured to use the optics 3110 todetect the pulsed light signals reflected back from the target ofinterest and feed back to the control unit 3102. Optionally, the controlunit 3102 includes a processor configured to process the pulsed lightsignals transmitted out and recaptured after reflection from the targetof interest, based on which a depth sensing result about the target canbe deduced. Optionally, the optics 3110 includes one or more opticalreceive elements configured to perform the detection function.Optionally, the additional optical elements include sensor, filter,photo detector, photoresistor, etc. which can be installed within a samepackage of the optics 3110 for the one or more optical transmitelements. On the other hand, the optics 3110 includes one or more beamsteering/projecting elements for guiding at least the remaining portionof the beam of white-color/IR light as a light source for illumination.Specially, this light source includes an IR illumination capability ontop of the white-color light illumination. Optionally, the beam forillumination could be further shaped and collimated to a 3D angle of 15degrees or less with enhanced directionality and reduced attenuation.Optionally, the beam white-color/IR light is additionally used to createa spatially dynamic illumination of the target of interest. Optionally,the laser light out of the GaN containing laser diode and IR-emittinglaser diode that is modulated to carry pulsed signals can be useddirectly as a probe of a handheld LIDAR system.

FIG. 23E is a simplified schematic diagram of a combination of GaNcontaining laser light and/or IR-emitting laser illumination systemintegrated with a depth sensing system according to yet anotheralternative embodiment of the present invention. This diagram is merelyan example, which should not unduly limit the scope of the claims. Oneof ordinary skill in the art would recognize many variations,alternatives, and modifications. As shown, the GaN containing laserand/or IR-emitting laser based illumination function integrated with adepth sensing function is provided in a portable lighting device 3150which can be configured to be a handheld device, a spot light device, abike light device, an accessory car light device, a drone light device,etc. In an embodiment, the portable lighting device 3150 issubstantially the same as the apparatus 3100 shown in FIG. 23D exceptthat the beam shaping optics 3105 is integrated in optics 3106 forvisible light shaping, projecting, and receiving sensing signal.Optionally, the beam shaping optics that is coupled to the wavelengthconverter member 3104 in the FIG. 23D is also configured to have a beamshaping optics that could both project the visible light forillumination and transmitting the light carrying the depth sensingsignal to target of interest. Optionally, the optics 3106 for visiblelight shaping, projecting, and receiving sensing signal is controlled bythe control unit 3102 with a drive electronics to perform the projectingfunction. Optionally, the optics 3106 for visible light shaping,projecting, and receiving sensing signal is configured to receive ordetect returned sensing signals (from the target of interest) and sendthe detected sensing signals back to the control unit 3102. The controlunit 3102 includes processor configured to handle both the transmittedsensing signals and returned sensing signals for completing depthsensing process. Optionally, the control unit 3012 is able to providedepth sensing results to a data port for exporting or a displayinterface of the portable lighting device 3150. Optionally, the portablelighting device 3150 includes a separate beam shaping unit forprojecting IR light beam for IR illumination and additionally IRdetection unit for an alternative depth sensing in addition to the depthsensing using visible light.

FIG. 23F is a simplified schematic diagram of a combination of GaNcontaining laser light and/or IR-emitting laser illumination systemintegrated with a depth sensing system according to still anotheralternative embodiment of the present invention. This diagram is merelyan example, which should not unduly limit the scope of the claims. Oneof ordinary skill in the art would recognize many variations,alternatives, and modifications. As shown, the GaN containing laserand/or IR-emitting laser based illumination function integrated with adepth sensing function is provided in a portable lighting device 3160which can be configured to be a handheld device, a spot light device, abike light device, an accessory car light device, a drone light device,etc. In an embodiment, the portable lighting device 3160 issubstantially the same as the apparatus 3150 shown in FIG. 23E exceptthat the optics 3107 for visible light shaping and projecting sensingsignal is separated from the optics 3108 for receiving returned sensingsignal. Optionally, the optics 3107 for visible light shaping andprojecting sensing signal is coupled to the wavelength converter member3104 to receive visible (white-color) light beam and process it undercontrol of the control unit 3102 to shape and project the visible lightbeam for illumination. Optionally, the same optics 3107 is alsocontrolled by the control unit 3102 with a drive electronics configuredto perform the projecting or scanning function to transmit the visiblelight beam carrying the depth sensing signal to a target of interest inthe field. Optionally, the optics 3108 for receiving returned sensingsignal is configured to receive or detect returned sensing signals (fromthe target of interest) and send the detected sensing signals back tothe control unit 3102. The control unit 3102 includes processorconfigured to handle both the transmitted sensing signals and returnedsensing signals for completing depth sensing process. Optionally, thecontrol unit 3012 is able to provide depth sensing results to a dataport for exporting or a display interface of the portable lightingdevice 3160. Optionally, the portable lighting device 3160 includes aseparate beam shaping unit for projecting IR light beam for IRillumination and additionally IR detection unit for an alternative depthsensing in addition to the depth sensing using visible light.

FIG. 23G is a simplified schematic diagram of an apparatus having acombination of GaN containing laser and IR-emitting laser illuminationsystem integrated with a data communication system according to yetanother embodiment of the present invention. This diagram is merely anexample, which should not unduly limit the scope of the claims. One ofordinary skill in the art would recognize many variations, alternatives,and modifications. In general, this apparatus is a portable lightingdevice for visible/IR light data communication. Optionally, theapparatus can be a portable communication device such as flashlight,spotlight, outdoor security light source configured with visible/IRlight communication for recreation, defense, security, search, andrescue etc. In general, the portable communication device includes everycomponents in one compact housing with internal power supply disposedtherein and one or more control switches and input ports configured atsurface of the compact housing. As shown in the figure, the apparatus3200 is configured with an internal power source 3201 to supply power toboth the laser-based illumination system and a data communicationsystem. Optionally, the internal power supply 3201 is a chargeable powersource which can receive charged electrical power from external inputs3290. For example, the external inputs 3290 include a charging portconnected to any residential or commercial electric-power socket.Optionally, the internal power supply 3201 is a compact chargeablebattery and the charging port is a USB-C port.

In the embodiment, the apparatus 3200 includes a control unit 3202including drive and modulate electronics configured to receive powerfrom the internal power supply 3201. The control unit 3202 is coupled toa laser device 3203 comprising a GaN containing laser diode and anIR-emitting laser diode. The control unit 3202 is configured to generatedrive signals to drive the laser device 3203 to produce laser lightemission with a first wavelength in violet or blue spectrum range fromthe GaN containing laser diode and/or an IR emission with a thirdwavelength in an infrared spectrum range from the IR-emitting laserdiode. The control unit 3202 also is configured to generate modulationsignals to modulate the laser light emission and/or IR emission based ondata signals inputted from a data port of the external inputs 3290.Optionally, the data port is a wired port like a USB port, or a wirelessinterface via WiFi or Bluetooth or other wireless communicationprotocol.

In the embodiment, the apparatus 3200 further includes a wavelengthconverting member 3204 configured to be integrated with the laser devicein a surface mount device (SMD) package with a common support member.The wavelength converting member 3204 is configured with a phosphormaterial to receive the laser light emission with the first wavelength.The phosphor material contains proper chemical ingredients that absorbthe laser light emission with the first wavelength and re-emit aphosphor emission with a second wavelength that is longer than the firstwavelength. Optionally, the phosphor emission is mixed partially withthe laser light emission (either the incident part or scattered part) toproduce a white-color light beam. In an embodiment, the wavelengthconverting member 3204 is configured with the phosphor material which isalso configured to substantially pass the IR emission with littleabsorption so that the IR emission is outputted from the wavelengthconverting member without major power loss and wavelength change.Optionally, either a white-color beam or an IR emission beam or acombination of both are outputted from the SMD package. Optionally, thewhite-color/IR emission beam carries data signals that are generated bymodulation performed in the control unit 3202.

In the embodiment, the apparatus 3200 also includes a beam shapingoptics 3205 coupled to the wavelength converting member 3204 andconfigured to adjust, collimate, and shape the white-color/IR emissionbeam and feed the shaped white-color/IR emission beam to optics 3210designed for projecting the light beam to a field target. Optionally,the optics 3210 includes one or more beam steering elements for beamconfining, focusing, amplifying, scanning, spatial-patterning,phase-modulating, or projecting so that the white-color/IR lightemission can be delivered as a directional electromagnetic radiation tothe desired places. Optionally, the same optics 3210 also includes anoptical transmitting device configured to transmit light signal carryingthe modulated data therein. The modulated data carried in thewhite-color/IR light emission come from the laser light modulated by thecontrol unit 3202 based on input data. Optionally, the white-color/IRlight emission transmitted out by the optics 3210 is used to provide avisible/IR light communication based on one or more different modulationand transmission protocol including LiFi or internet connection.

FIG. 23H is a simplified schematic diagram of an apparatus having acombination of GaN containing laser and IR-emitting laser illuminationsystem integrated with a data communication system according to stillanother embodiment of the present invention. This diagram is merely anexample, which should not unduly limit the scope of the claims. One ofordinary skill in the art would recognize many variations, alternatives,and modifications. As shown, the apparatus 3250 is an integratedlighting device with laser-based illumination and data communicationfunctions. Optionally, the apparatus 3250 is substantially the same asthe apparatus 3200 shown in FIG. 23G except that the beam shaping optics3205 is fully absorbed in the optics 3210 for transmitting and receivingvisible/IR light data communication signals. In the embodiment, theoptics 3210 is configured to receive a white-color emission and/or aninfrared emission from the wavelength converting member 3204 to form alight beam and project the light beam carrying communication data downto a field receiver. In some embodiments, the apparatus 3250 can beconfigured to a portable communication device such as flashlight,spotlight, outdoor security light source, wearable light source,bike/car mountable light source, or drone light source that isconfigured with a compact housing for performing visible/IR lightcommunication function for recreation, defense, security, search, andrescue etc.

In a specific aspect, the present disclosure provides a portablelighting device that integrate a laser-based white light source with oneor more functional units of IR illumination, depth-sensing, andlight-communication in some embodiments. In particular, an example isshown below in FIG. 24 . This diagram is merely an example, which shouldnot unduly limit the scope of the claims. One of ordinary skill in theart would recognize many variations, alternatives, and modifications. Asshown, this portable lighting device 2400 is provided with a compacthousing 2410 in substantially cylinder shape, e.g., a flashlight-likemodule, with a front aperture 2472 to output one or more light beams aseither an illumination light beam or a sensing light beam or a lightbeam carrying communication signals in a relative narrow 3D angle range.Optionally, the illumination light beam is a white light beam generatedby a laser-based white light source. Optionally, the illumination lightbeam includes an infrared light beam generated by an IR-emitting laserdiode. Optionally, either or both the white light and IR light can beemployed as a sensing light beam or for visible/IR light communication.

Optionally, the compact housing 2410 is configured in a funnel shape,e.g., a spotlight-like module, with a front aperture 2472 to output oneor more light beams as either an illumination light beam or a sensinglight beam or a light beam carrying communication signals in a wide 3Dangle range. Optionally, the compact housing 2410 is configured invarious other shapes like box, cube, ball, half-dome, triangle pyramidfor various security light settings.

In an embodiment, the portable lighting device 2400 includes a firstpump-light device including a gallium and nitrogen (GaN) containinglaser diode comprised with an optical cavity having an optical waveguideregion and one or more facet regions in a surface-mount-device (SMD)package 2432 (e.g., as seen in FIGS. 17A, 17B, 18A, 18B, 18C, 19A, and19B). The gallium and nitrogen containing laser diode formed in the SMDpackage 2432 is configured to output directional electromagneticradiation characterized by a first peak wavelength through at least oneof the facet regions. Optionally, the GaN containing laser diode isconfigured to lase a directional electromagnetic radiation characterizedwith the first peak wavelength in the violet wavelength region of 390 nmto 420 nm or the blue wavelength region of 420 nm to 480 nm. Optionally,the GaN containing laser diode is configured to lase the directionalelectromagnetic radiation characterized with the first peak wavelengthin the ultraviolet wavelength region of 270 nm to 390 nm or the greenwavelength region from 480 nm to 540 nm. The portable lighting device2400 further includes a first wavelength converter optically coupled tothe pathway to receive the directional electromagnetic radiation fromthe first pump-light device.

Optionally, the first wavelength converter is configured to convert atleast a fraction of the directional electromagnetic radiation with thefirst peak wavelength (violet or blue color) to at least a second peakwavelength (e.g., yellow color) that is longer than the first peakwavelength and to generate a visible light emission such as awhite-color emission in a first pathway. Optionally, the firstwavelength converter is also formed in the SMD package 2432. Optionally,the first wavelength converter is comprised of a phosphor materialincluding a ceramic yttrium aluminum garnet (YAG) doped with Ce, or asingle crystal YAG doped with Ce, or a powdered YAG comprising a bindermaterial. Optionally, the phosphor material has an optical conversionefficiency of at least 50 lumen per optical watt.

Optionally, the portable lighting device 2400 includes a secondwavelength converter made by a phosphor member configured for convertinga fraction of the directional electromagnetic radiation from the firstpump-light device to generate an IR emission in a second pathway with athird peak wavelength in infrared range of about 850 to 900 nm or in abroader range between 760 nm and 3 μm. Optionally, the second wavelengthconverter is configured to transmit and/or scatter the infraredelectromagnetic radiation with minimal absorption. Optionally, the firstwavelength converter and the second wavelength converter are a samephosphor member configured with stacked or composite broadbandwavelength-converting materials and the second pathway is substantiallyoverlapping with the first pathway.

Optionally, the portable lighting device 2400 includes a secondpump-light device including a red or near-IR emitting laser diode formedfrom a material operating in the red or IR wavelength region, such as agallium and arsenic containing material or an indium and phosphorouscontaining material. The output electromagnetic emission from the secondpump-light device is configured to preferentially excite an IR emittingphosphor member without substantially exciting the visible-lightphosphor member. Optionally, the second pump-light device is formed in asame SMD package 2432 as the first pump-light device. Optionally, theinfrared emitting laser diode associated with the second pump-lightdevice is configured to lase the infrared electromagnetic radiationcharacterized by a third wavelength in the 700 nm to 1100 nm range, awavelength in the 1100 to 2500 nm range, or a wavelength in the 2500 nmto 15000 nm range. Optionally, the infrared emitting laser diode isbased on interband electron-hole recombination such as a quantum welllaser diode, or is based on a quantum cascade laser diode operating withintraband or interband transitions. Optionally, the infrared emittinglaser diode is based on an edge-emitting cavity design or a verticalcavity emitting design. Optionally, the infrared emitting laser diode isbased on a material system comprising GaAs, InP, InGaAs, InAs, InAlAs,AlGaAs, AlInGaP, InGaAsP, or InGaAsSb, or some combination thereof.Optionally, all the laser diodes or wavelength converting members in theSMD package 2432 shares a common heatsink 2434.

In the embodiment, the portable lighting device 2400 includes a portablepower supply 2440 fully installed inside the compact housing 2410. Aprinted circuit board assembly (PCBA) 2450 is disposed in the compacthousing 2410 to support a controller 2452 which includes one or moredrivers. At least a driver is used to condition the power from theportable power supply 2440 to provide driving current/voltage to driverthe first or the second pump-light devices in the SMD package 2432.

Optionally, the portable power supply 2440 is a battery. Optionally, thebattery is a high-capacity rechargeable battery. Optionally, theportable power supply 2440 is configured with a full protectioncircuitry for over-charge protection, over-discharge protection, andshort-circuit protection. It is also configured to be under NTCtemperature protection. Optionally, it provides a capacity up to 38 Wh.Optionally, the charging of the battery is conducted through a USB port2462.

Optionally, the controller 2452 includes a modulator configured tomodulate amplitude or phase of the light emitted from either oroptionally both the first pump-light device and the second pump-lightdevice to generate data stream. The modulated light carrying the datastream is transmitted out of the front aperture 2422 for visible/IRlight communication with any receiver down in the field. Optionally, thedata stream is based on data input through an input port 2464 which isconnected to the modulator in controller 2452 disposed on the PCBA 2450.

Optionally, the controller 2452 includes a pulse generator to modulatethe visible or IR laser emitted from the laser device formed in the SMDpackage 2432 and generate light pulses configured as sensing signalswhich are outputted through the front aperture 2422 of the compacthousing 2410. The sensing signals are intended to be projected tocertain target of interest from which a reflection of the sensingsignals can be detected by one or more sensors 2434 installed inside thefront aperture 2422. The sensors include photo diode, photoresistor,infrared sensor, camera, color sensor, voltage sensor, etc. Optionally,the sensors 2434 are in a circuitry connected with controller 2452 whichcontains a processor to perform various calculation to yield detectionresults or generate feedback signals for controlling the driver fortuning emissions of the pump-light devices depending on specifiedsensing applications including depth sensing, ranging finding, fieldmapping, image capturing, motion sensing, identity verification, etc.

In some embodiments, the portable lighting device 2400 includes one ormore optical elements 2424 disposed inside the compact housing 2410 nearthe front aperture 2422. The optical elements 2424 are generallyreferred to one or more beam shaping optical elements and one or morebeam steering optical elements. The beam shaping optical elementsinclude one or a combination of multiple optical devices or elementsselected from a list of slow axis collimating lens, fast axiscollimating lens, aspheric lens, ball lens, total internal reflector(TIR) optics, parabolic lens optics, refractive optics, andmicro-electromechanical system (MEMS) mirrors configured to direct,collimate, focus the white-color spectrum to at least modify an angulardistribution thereof. The beam steering optical elements include one ora combination of multiple optical devices or elements selected frommicro-electromechanical system (MEMS) mirror, digital light processing(DLP) chip, digital mirror device (DMD), and liquid crystal on silicon(LCOS) chip, lens, a reflector, a projector, a transmitter, an amplifierfor steering, patterning, or pixelating the white-color light or IRelectromagnetic radiation. Optionally, the front aperture 2422 can beconfigured to be a lens, a transmitter, an amplifier, a filter, acollimator, etc. In case that the portable lighting device 2400 is usedas an illuminator (with either visible or IR illumination), the whitelight or IR electromagnetic radiation out of the SMD package 2432 isguided or directed by the beam steering optical element 2424 andtransmitted through the front aperture 2422 to illuminate any target ofinterest. Optionally, the portable lighting device 2400 also includes aproper sensor or detector 2434 like an IR camera disposed near the frontaperture for capturing IR mapping image of the illuminated target ofinterest. In a preferred embodiment, the IR illumination and the whitelight illumination emission share at least a common beam shaping elementsuch that the illumination areas of the white light and the IRelectromagnetic radiation can be approximately super-imposed. In casethat the portable lighting device 2400 is used as a depth-sensingdevice, the one or more optical elements 2424 may be configured to shapeor focus or direct the beam of white light emission and/or the IRemission. At the same time, the one or more sensors or detectors 2434for detecting reflected sensing signals should be disposed near thefront aperture 2422 and the controller 2452 includes a processorconnected to the sensors to receive the reflected sensing signals fordeducing information like depth, topography, and target identification,etc. Optionally, the one or more sensors or detectors 2434 include aphotodiode, a photoresistor, a CCD camera, an antenna, a scanning mirroror a microdisplay coupled to a photodiode to convert the reflected lightsignals to electrical signals. In case that the portable lighting device2400 is used as a device for visible/IR light communication, the one ormore optical elements 2424 may be configured to an optical transmitterto deliver the white light or infrared light carrying certain datastream to intended receivers in the field or to dynamically drive beamsteering in spatial and timing modulations to project different lightpatterns, fixed or timely-changed, that carry different visualinformation. Optionally, the data stream is delivered from a smartdevice to the portable lighting device 2400 via at least one data inputport 2464 through a wired or wireless communication protocol. The datastream is implemented by a laser driver module included in thecontroller 2452 to modulate the laser light emitted from the laserdevice in the SMD package to generate modulated light signal at amodulation frequency range of about 50 to 500 MHz, 500 MHz to 5 GHz, 5GHz to 20 GHz, or greater than 20 GHz. The optical transmitterassociated with the one or more optical elements 2424 is configured totransmit the white-light emission and/or IR emission that carries themodulated light signal for a proper receiver in the field.

In the embodiment, the portable lighting device 2410 includes one ormore switches 2470 disposed on surface of the compact housing 2410 yetconnected to the portable power supply 2440 to activate the GaN laserdiode and IR-emitted laser diode for selecting white light or IR lightillumination, sensing, or communication. Optionally, the one or moreswitches 2470 includes one for activate other light-emitting diodeswhich can be also disposed along a peripheral ring of the front aperture2422 for providing regular flashlight function. A ring lens can beinstalled along the peripheral ring of the front aperture 2422 tooptimize the illumination of the regular flashlight. Optionally, avisual interface (although not shown) can be disposed also on thesurface of the compact housing 2410 yet connected to the controller 2452for displaying sensing results, communication data, error messages,power-level and charging progress, and other information.

In another specific aspect, the present disclosure provides anattachable lighting module that can be mounted or integrated with aportable apparatus or mobile machine to perform visible-light/IRillumination, depth-sensing, and light-communication in someembodiments. FIG. 25 is a simplified diagram of an attachable lightingmodule configured for visible-light/infrared light illumination, depthsensing, and communication according to some embodiments of the presentinvention. This diagram is merely an example, which should not undulylimit the scope of the claims. One of ordinary skill in the art wouldrecognize many variations, alternatives, and modifications. As shown,the attachable lighting module 4010 is attached to a portable apparatusor mobile machine 4100 to form a mobile lighting machine 4000 forperforming functions of visible-light/IR illumination, depth-sensing,and light-communication. Optionally, the attachable lighting module 4010is based on a pump-light device having at least one gallium-and-nitrogencontaining laser diode driven by at least a driver to emit a laser lightin terms of a directional electromagnetic radiation having a first peakwavelength in blue or violet spectrum to at least an optical pathway anda wavelength converter configured to couple with the optical pathway toconvert at least a fraction of the directional electromagnetic radiationto a phosphor emission with a second peak wavelength such as a yellowspectrum longer than the first wavelength. The phosphor emissioncombined with the laser light to generate a white-color emission.Optionally, the portable apparatus or mobile machine 4100 includes butnot limited to a land-running automobile, a drone, a marine/submarinevehicle, an underwater tool, a flying car, an airplane, a helicopter, anATV. Optionally, the attachable lighting module 4010 can be configuredto be a flash-light type with a single projector (see FIG. 24 ) or alight bar type with multiple projectors in a row (see FIG. 25 ).Commonly, the attachable lighting module 4010 is configured to drawpower from the portable apparatus or mobile machine 4100, based on thepower a driver in a control unit can drive the generation of thewhite-color emission.

As shown in FIG. 25 , the attachable lighting module 4010 is configuredto be a light bar configuration with an elongated housing 4001 and oneor more attachment member 4020 configured to attach with the portableapparatus or mobile machine 4100. Optionally, the attachable lightingmodule 4010 can be made to be a built-in member within a custom-designedmobile lighting machine 4000. Optionally, the attachable lighting module4010 itself is a mass-manufactured module that can be freely attached toa body of any portable apparatus or mobile machine 4100 to from themobile lighting machine 4000.

In an embodiment, as shown in FIG. 25 , the housing 4001 has a top capmember 4001A lifted to show that a pump-light device 4004 is installedtherein. Optionally, the pump-light device 4004 is configured with anoptical cavity including optical waveguide region and one or more facetregions disposed on a common support member in a surface mount device(SMD) package. The pump-light device includes at least onegallium-and-nitrogen containing laser diode configured at the SMDpackage to output at least a directional electromagnetic radiationcharacterized by a first peak wavelength through at least one of thefacet regions. Optionally, the SMD package of the also includes awavelength converter disposed to the common support member in at least apathway to receive the directional electromagnetic radiation andconfigured to convert at least a fraction of the directionalelectromagnetic radiation with the first peak wavelength to at least asecond peak wavelength that is longer than the first peak wavelength andto generate a white-color emission comprising at least the second peakwavelength. Optionally, the pump-light device 4004 further includes atleast an infrared-emitting laser diode configured at the same SMDpackage to output an infrared radiation directed through the at leastpathway to the wavelength converter which substantially passes it withminimum absorption to emit an IR emission.

In the embodiment, the housing 4001 also is configured to enclose atleast a beam shaping unit 4005 configured to receive, direct/re-direct,focus, collimate, split the white-color emission or the IR emission thatoutputted from the wavelength converter associated with the pump-lightdevice 4004. Optionally, the beam shaping unit 4005 can generate one ormore beams to multiple outlets configured at a front aperture 4009 ofthe housing 4001. For example, there are eight outlets at the frontaperture 4009 effectively configured to be eight independent sources.Optionally, the pump-light device 4004 includes one laser diode as itproduces laser light which has much brighter luminance than typical LEDso that the beam shaping unit 4005 can split one white-color emission tothe eight outlets each with strong-enough luminance for performingillumination function. Optionally, the pump-light device 4004 includesmultiple laser diodes. Optionally, the pump-light device 4004 includestwo types of laser diodes such as GaN-based laser diode and Infraredlaser diode to allow visible-light/IR-light dual illumination. Forexample, a white-color source head 4011 and an IR source head 4012 areprovided to each outlet (see FIG. 25 ).

In the embodiment, the attachable lighting module 4010 includes a beamsteering unit 4015 configured with each outlet of the front aperture4009 to project or transmit a beam of white-color emission or IRemission. Optionally, the beam steering unit 4015 includes one moreoptical elements for respectively projecting a beam of eitherwhite-color emission or IR emission for single wavelength illuminationon target of interest. Optionally, the beam steering unit 4015 includesone more optical elements configured to project both a beam ofwhite-color emission and a beam of IR emission to achievedual-wavelength illumination.

In some embodiments, the control unit (not explicitly shown) enclosed inthe housing 4001 of the attachable lighting module 4010 is configured tomodulate the laser light emitted from the GaN-containing laser diode orInfrared-emitting laser diode to generate modulated signals. Thesemodulated signals are carried by the white-color emission and/or IRemission directed to the front aperture 4009. A switch in the controlunit can make a selection of activating either the white-color emissionfor visible-light illumination or the IR emission for infraredillumination.

In an embodiment, the control unit is configured to generate pulsedsignals from the laser light. The beam steering unit 4015 includes oneor more optical transmitting elements configured to transmit a beam ofthe white-color emission and/or a beam of IR emission carrying thepulsed signals to a target of interest for depth sensing. Optionally,the attachable lighting module 4010 has multiple outlets at frontaperture 4009, each of which is configured with one or more opticaltransmitting elements to transmit at least one beam carrying the pulsedsignals. As shown in FIG. 25 , the attachable lighting module 4010further includes one or more detectors 4016 disposed near the frontaperture 4009 for receiving returned pulsed signals. Optionally, eachdetector 4016 is disposed near an optical transmit element at acorresponding outlet of the front aperture 4009 and is configured todetect the returned pulsed signal from a corresponding target ofinterest. The detector 4016 can feed back the detected signal to thecontrol unit which is configured to deduce depth information based onboth the transmitted pulsed signal and the returned pulsed signal.Optionally, the detector 4016 is configured with a single detectionbased on the white-color emission only. Optionally, the detector 4016 isconfigured with dual detections based on both the white-color emissionand the IR emission. A switch in the control unit can make a selectionof activating either the white-color emission or the IR emission fordepth sensing.

In another embodiment, the control unit is configured to generate phaseor intensity modulation signals from the laser light to carryingcommunication data. The beam steering unit 4015 includes one or moreoptical transmitting elements configured to transmit a beam of thewhite-color emission and/or a beam of IR emission to deliver thecommunication data to a field receiver. Optionally, the control unitincludes a switch (not explicitly shown) configured to either select tooperate the GaN-containing laser diode to generate a beam of white-coloremission for visible light communication or select to operate theinfrared-emitting laser diode to generate a beam of IR emission forinfrared light communication.

Applications for such portable lighting apparatus includesindividually-executable operations like spotlighting, depth detection,range finding, IR imaging, projection display, spatially dynamiclighting, LIDAR, WiFi, LiFi, visible/IR light communication, generallighting, commercial lighting and display, internet connection, defenseand security, search and rescue, industrial processing, internetcommunications, or agriculture or horticulture. In some embodiments,applications also can be applied to anywhere there is aesthetic,informational or artistic value in the color point, position or shape ofa spotlight being dynamically controlled based on the input from one ormore sensors. The primary advantage of the apparatus to suchapplications is that the apparatus may transition between severalconfigurations, with each configuration providing optimal lighting fordifferent possible contexts. Some example contexts that may requiredifferent quality of lighting include: general lighting, highlightingspecific objects in a room, spot lighting that follows a moving personor object, lighting that changes color point to match time of day orexterior or ambient lighting, among others.

As an example use case, the apparatus could be used as a light sourcefor illuminating works of art in a museum or art gallery. Motion sensorswould trigger the change in the shape and intensity of the emitted spotof light from a spatial and color configuration intended for generallighting to a configuration that highlights in an ascetically pleasingway the work of art corresponding to the triggering motion sensor. Sucha configuration would also be advantageous in stores, where theapparatus could provide general illumination until a triggering inputcauses it to preferentially illuminate one or more items for sale.

The apparatus would be advantageous in lighting applications where oneneeds to trigger transmission of information based on the input ofsensors. As an exemplary application, one may utilize the apparatus as acar head-light. Measurements from a LIDAR or image recognition systemwould detect the presence of other vehicles in front of the car andtrigger the transmission of the cars location, heading and velocity tothe other vehicles via VLC.

Applications include selective area VLC as to only transmit data tocertain locations within a space or to a certain object which isdetermined by sensors—spatially selective WiFi/LiFi that can track therecipients location and continuously provide data. You could even dospacetime division multiplexing where convoluted data streams are sentto different users or objects sequentially through modulation of thebeam steering device. This could provide for very secure end user datalinks that could track user's location.

In an embodiment, the apparatus is provided with information about thelocation of a user based on input from sensors or other electronicsystems for determining the location of individuals in the field of theview of the apparatus. The sensors might be motion detectors, digitalcameras, ultrasonic range finders or even RF receivers that triangulatethe position of people by detecting radio frequency emissions from theirelectronics. The apparatus provides visible light communication throughthe dynamically controllable white light spot, while also being able tocontrol the size and location of the white light spot as well as rasterthe white light spot quickly enough to appear to form a wide spot ofconstant illumination. The determined location of a user with respect tothe apparatus can be used to localize the VLC data transmission intendedfor a specific user to only in the region of the field of view occupiedby the specific user. Such a configuration is advantageous because itprovides a beam steering mechanism for multiple VLC transmitters to beused in a room with reduced interference. For example, two conventionalLED-light bulb-based VLC transmitters placed adjacent to one another ina room would produce a region of high interference in the region of theroom where the emitted power from both VLC transmitters incident on auser's VLC receiver is similar or equal. Such an embodiment isadvantageous in that when two such light sources are adjacent to oneanother the region containing VLC data transmission of the firstapparatus is more likely to overlap a region from the second apparatuswhere no VLC data is being transmitted. Since DC offsets in receivedoptical power are easy to filter out of VLC transmissions, this allowsmultiple VLC enabled light sources to be more closely packed while stillproviding high transmission rates to multiple users.

In some embodiments, the apparatus received information about where theuser is from RF receivers. For example, a user may receive data usingVLC but transmits it using a lower-bandwidth WiFi connection.Triangulation and beam-forming techniques can be used to pinpoint thelocation of the user within a room by analyzing the strength of theuser's WiFi transmission at multiple WiFi transmitter antennas.

In some embodiments, the user transmits data either by VLC or WiFi, andthe location of the user is determined by measuring the intensity of theVLC signal from the apparatus at the user and then transmitting thatdata back to the apparatus via WiFi or VLC from the user's VLC enableddevice. This allows the apparatus to scan the room with a VLCcommunication spot and the time when a user detects maximum VLC signalis correlated to the spot position to aim the VLC beam at the user.

In an embodiment, the apparatus is attached to radio-controlled orautonomous unmanned aircraft. The unmanned aircraft could be drones,i.e. small-scale vehicles such as miniature helicopters, quad-copters orother multi-rotor or single-rotor vertical takeoff and landing craft,airplanes and the like that were not constructed to carry a pilot orother person. The unmanned aircraft could be full-scale aircraftretrofitted with radio-controls or autopilot systems. The unmannedaircraft could be a craft where lift is provided by buoyancy such asblimps, dirigibles, helium and hydrogen balloons and the like.

Addition of VLC enabled, laser-based dynamic white-light sources tounmanned aircraft is a highly advantageous configuration forapplications where targeted lighting must be provided to areas withlittle or no infrastructure. As an exemplary embodiment, one or more ofthe apparatuses are provided on an unmanned aircraft. Power for theapparatuses is provided through one or more means such as internal powerfrom batteries, a generator, solar panels provided on the aircraft, windturbines provided on the aircraft and the like or external powerprovided by tethers including power lines. Data transmission to theaircraft can be provided either by a dedicated wireless connection tothe craft or via transmission lines contained within the tether. Such aconfiguration is advantageous for applications where lighting must beprovided in areas with little or no infrastructure and where thelighting needs to be directional and where the ability to modify thedirection of the lighting is important. The small size of the apparatus,combined with the ability of the apparatus to change the shape and sizeof the white light spot dynamically as well as the ability of theunmanned aircraft to alter its position either through remote control bya user or due to internal programming allow for one or more of theseaircraft to provide lighting as well as VLC communications to a locationwithout the need for installation of fixed infrastructure. Situationswhere this would be advantageous include but are not limited toconstruction and road-work sites, event sites where people will gatherat night, stadiums, coliseums, parking lots, etc. By combining a highlydirectional light source on an unmanned aircraft, fewer light sourcescan be used to provide illumination for larger areas with lessinfrastructures. Such an apparatus could be combined with infra-redimaging and image recognition algorithms, which allow the unmannedaircraft to identify pedestrians or moving vehicles and selectivelyilluminate them and provide general lighting as well as networkconnectivity via VLC in their vicinity.

In some preferred embodiments the smart light source is used in Internetof Things (IoT), wherein the laser based smart light is used tocommunicate with objects such as household appliances (i.e.,refrigerator, ovens, stove, etc.), lighting, heating and coolingsystems, electronics, furniture such as couches, chairs, tables, beds,dressers, etc., irrigation systems, security systems, audio systems,video systems, etc. Clearly, the laser based smart lights can beconfigured to communicate with computers, smart phones, tablets, smartwatches, augmented reality (AR) components, virtual reality (VR)components, games including game consoles, televisions, and any otherelectronic devices.

In some embodiments, the apparatus is used for augmented realityapplications. One such application is as a light source that is able toprovide a dynamic light source that can interact with augmented realityglasses or headsets to provide more information about the environment ofthe user. For example, the apparatus may be able to communicate with theaugmented reality headset via visible light communication (LiFi) as wellas rapidly scan a spot of light or project a pattern of light ontoobjects in the room. This dynamically adjusted pattern or spot of lightwould be adjusted too quickly for the human eye to perceive as anindependent spot. The augmented reality head-set would contain camerasthat image the light pattern as they are projected onto objects andinfer information about the shape and positioning of objects in theroom. The augmented reality system would then be able to provide imagesfrom the system display that are designed to better integrate withobjects in the room and thus provide a more immersive experience for theuser.

For spatially dynamic embodiments, the laser light or the resultingwhite light must be dynamically aimed. A MEMS mirror is the smallest andmost versatile way to do this, but this text covers others such as DLPand LCOS that could be used. A rotating polygon mirror was common in thepast, but requires a large system with motors and multiple mirrors toscan in two or more directions. In general, the scanning mirror will becoated to produce a highly reflective surface. Coatings may includemetallic coatings such as silver, aluminum and gold among others. Silverand Aluminum are preferred metallic coatings due to their relativelyhigh reflectivity across a broad range of wavelengths. Coatings may alsoinclude dichroic coatings consisting of layers of differing refractiveindex. Such coatings can provide exceptionally high reflectivity acrossrelatively narrow wavelength ranges. By combining multiple dichroic filmstacks targeting several wavelength ranges a broad spectrum reflectivefilm can be formed. In some embodiments, both a dichroic film and ametal reflector are utilized. For example, an aluminum film may bedeposited first on a mirror surface and then overlaid with a dichroicfilm that is highly reflective in the range of 650-750 nm. Sincealuminum is less reflective at these wavelengths, the combined filmstack will produce a surface with relatively constant reflectivity forall wavelengths in the visible spectrum. In an example, a scanningmirror is coated with a silver film. The silver film is overlaid with adichroic film stack which is greater than 50% reflective in thewavelength range of 400-500 nm.

In some embodiments, the signal from one or more sensors is inputdirectly into the steering element driver, which is provided withcircuits that adapt sensor input signals into drive currents or voltagesfor the one or more scanning mirrors. In other embodiments, a computer,microcontroller, application specific integrated circuit (ASIC) or othercontrol circuit external to the steering element driver is provided andadapts sensor signals into control signals that direct the steeringelement driver in controlling the one or more scanning mirrors.

In some embodiments, the scanning mirror driver responds to input frommotion sensors such as a gyroscope or an accelerometer. In an exampleembodiment, the white light source acts as a spot-light, providing anarrowly diverging beam of white light. The scanning mirror driverresponds to input from one or more accelerometers by angling the beam oflight such that it leads the motion of the light source. In an example,the light source is used as a hand-held flash-light. As the flash-lightis swept in an arc the scanning mirror directs the output of the lightsource in a direction that is angled towards the direction of motion ofthe flash light. In an example embodiment, the white light source actsas a spot-light, providing a narrowly diverging beam of white light. Thescanning mirror driver responds to input from one or more accelerometersand gyroscopes by directing the beam such that it illuminates the samespot regardless of the position of the light source. An application forsuch a device would be self-aiming spot-lights on vehicles such ashelicopters or automobiles.

In an embodiment, the dynamic white light source could be used toprovide dynamic head-lights for automobiles. Shape, intensity, and colorpoint of the projected beam are modified depending on inputs fromvarious sensors in the vehicle. In an example, a speedometer is used todetermine the vehicle speed while in motion. Above a critical thresholdspeed, the headlamp projected beam brightness and shape are altered toemphasize illumination at distances that increase with increasing speed.In another example, sensors are used to detect the presence of streetsigns or pedestrians adjacent to the path of travel of the vehicle. Suchsensor may include: forward looking infra-red, infra-red cameras, CCDcameras, cameras, Light detection and ranging (LIDAR) systems, andultrasonic rangefinders among others.

In an example, sensors are used to detect the presence of front, rear orside windows on nearby vehicles. Shape, intensity, and color point ofthe projected beam are modified to reduce how much of the headlight beamshines on passengers and operators of other vehicles. Suchglare-reducing technology would be advantageous in night-timeapplications where compromises must be made between placement of lampson vehicles optimized for how well an area is illuminated and placementof the beam to improve safety of other drivers by reducing glare.

At present, the high and low beams are used with headlights and thedriver has to switch manually between them with all known disadvantages.The headlight horizontal swivel is used in some vehicles, but it iscurrently implemented with the mechanical rotation of the wholeassembly. Based on the dynamic light source disclosed in this invention,it is possible to move the beam gradually and automatically from thehigh beam to low beam based on simple sensor(s) sensitive to thedistance of the approaching vehicle, pedestrian, bicyclist or obstacle.The feedback from such sensors would move the beam automatically tomaintain the best visibility and at the same time prevent blinding ofthe driver going in the opposite direction. With 2D scanners and thesimple sensors, the scanned laser-based headlights with horizontal andvertical scanning capability can be implemented.

Optionally, the distance to the incoming vehicles, obstacles, etc. orlevel of fog can be sensed by a number of ways. The sensors couldinclude the simple cameras, including infrared one for sensing in dark,optical distance sensors, simple radars, light scattering sensor, etc.The distance would provide the signal for the vertical beam positioning,thus resulting in the optimum beam height that provides best visibilityand does not blind drivers of the incoming vehicles.

In an alternative embodiment, the dynamic white light source could beused to provide dynamic lighting in restaurants based on machine vision.An infra-red or visible light camera is used to image a table withdiners. The number and positions or diners at the table are identifiedby a computer, microcontroller, ASIC or other computing device. Themicrocontroller then outputs coordinated signals to the laser driver andthe scanning mirror to achieve spatially localized lighting effects thatchange dynamically throughout the meal. By scanning the white light spotquickly enough the light would appear to the human eye to be a staticillumination. For example, the white light source might be provided withred and green lasers which can be used to modulate the color point ofthe white light illuminating individual diners to complement theirclothing color. The dynamic white light source could preferentiallyilluminate food dishes and drinks. The dynamic white light source couldbe provided with near-UV laser sources that could be used to highlightcertain objects at the table by via fluorescence by preferentiallyilluminating them with near-UV light. The white light source couldmeasure time of occupancy of the table as well as number of food itemson the table to tailor the lighting brightness and color point forindividual segments of the meal.

Such a white light source would also have applications in other venues.In another example use, the dynamic white light source could be used topreferentially illuminate people moving through darkened rooms such astheaters or warehouses.

In another alternative embodiment, the dynamic white light source couldbe used to illuminate workspace. In an example, human machineinteraction may be aided in a factory by using dynamically changingspatial distributions of light as well as light color point to provideinformation cues to workers about their work environments and tasks. Forexample, dangerous pieces of equipment could be highlighted in a lightspot with a predetermined color point when workers approach. As anotherexample, emergency egress directions customized for individual occupantsbased on their locations could be projected onto the floor or othersurfaces of a building.

In other embodiments, individuals would be tracked using triangulationof RFID badges or triangulation of Wi-Fi transmissions or other meansthat could be included in devices such as cell phones, smart watches,laptop computers, or any type of device.

In an alternative aspect, the present disclosure provides a smart lightsystem with color and brightness dynamic control. The smart light systemincludes a microcontroller configured to receive input information forgenerating one or more control signals. Further, the smart light systemincludes a laser device configured to be driven by at least one of theone or more control signals to emit at lease a first laser beam with afirst peak wavelength in a color range of violet or blue spectrum and asecond laser beam with a second peak wavelength longer than the firstpeak wavelength. Additionally, the smart light system includes a pathwayconfigured to dynamically guide the first laser beam and the secondlaser beam. The smart light system further includes a wavelengthconverting member configured to receive either the first laser beam orthe second laser beam from the pathway and configured to convert a firstfraction of the first laser beam with the first peak wavelength to afirst spectrum with a third peak wavelength longer than the first peakwavelength or convert a second fraction of the second laser beam withthe second peak wavelength to a second spectrum with a fourth peakwavelength longer than the second peak wavelength. The first spectrumand the second spectrum respectively combine with remaining fraction ofthe first laser beam with the first peak wavelength and the second laserbeam with the second peak wavelength to reemit an output light beam of abroader spectrum dynamically varied from a first color point to a secondcolor point. Furthermore, the smart light system includes a beam shapingoptical element configured to collimate and focus the output light beamand a beam steering optical element configured to direct the outputlight beam. The smart light system further includes a beam steeringdriver coupled to the microcontroller to receive some of the one or morecontrol signals based on input information for the beam steering opticalelement to dynamically scan the output light beam substantially in whitecolor to provide spatially modulated illumination and selectively directone or more of the multiple laser beams with the first peak wavelengthsin different color ranges onto one or more of multiple target areas orinto one or more of multiple target directions in one or more selectedperiods. Moreover, the smart light system includes one or more sensorsconfigured in a feedback loop circuit coupled to the controller. The oneor more sensors are configured to provide one or more feedback currentsor voltages based on the various parameters associated with the targetof interest detected in real time to the controller with one or more oflight movement response, light color response, light brightnessresponse, spatial light pattern response, and data signal communicationresponse being triggered.

Optionally, the laser device includes one or more first laser diodes foremitting the first laser beam with the first peak wavelength in violetspectrum ranging from 380 to 420 nm or blue spectrum ranging from 420 to480 nm.

Optionally, the laser device includes one or more second laser diodesfor emitting the second laser beam with the second peak wavelength inred spectrum ranging from 600 to 670 nm, or in green spectrum rangingfrom 480 nm to 550 nm, or in another blue spectrum with the second peakwavelength longer than the first peak wavelength.

Optionally, the one or more first laser diodes include an active regionincluding a gallium and nitrogen containing material configured to bedriven by the one or more driving currents.

Optionally, the gallium and nitrogen containing material includes one ormore of GaN, AlN, InN, InGaN, AlGaN, InAlN, InAlGaN.

Optionally, the one or more second laser diodes emitting in the red orinfrared region include an active region including a gallium and arseniccontaining material or an indium and phosphorous containing materialconfigured to be driven by the one or more driving currents.

Optionally, the wavelength converting member includes a first phosphormaterial selected for absorbing a first ratio of the first laser beamwith the first peak wavelength in the violet spectrum and converting toa first spectrum with the third peak wavelength longer than the firstpeak wavelength to emit a first output light beam with a first colorpoint, a second phosphor material selected for absorbing a second ratioof the first laser beam with the first peak wavelength in the bluespectrum and converting to a second spectrum with the third peakwavelength longer than the first peak wavelength to emit a second outputlight beam with a second color point, a third phosphor material selectedfor absorbing a third ratio of the second laser beam with the secondpeak wavelength and converting to a third spectrum with the fourthwavelength longer than the second peak wavelength to emit a third outputlight beam with a third color point.

Optionally, the pathway includes an optical fiber to guide either thefirst laser beam or the second laser beam to the wavelength convertermember disposed remotely as a remote light source.

Optionally, the pathway includes a waveguide for guiding either thefirst laser beam or the second laser beam to the wavelength convertermember to generate the output light beam with a dynamically varyingcolor point.

Optionally, the pathway includes free-space optics devices.

Optionally, the beam shaping optical element includes one or acombination of more optical elements selected a list of slow axiscollimating lens, fast axis collimating lens, aspheric lens, ball lens,total internal reflector (TIR) optics, parabolic lens optics, refractiveoptics, interference optics, and micro-electromechanical system (MEMS)mirrors configured to direct, collimate, focus the output light beamwith modified angular distribution thereof.

Optionally, beam steering optical element is selected from one of amicro-electromechanical system (MEMS) mirror, a digital light processing(DLP) chip, a digital mirror device (DMD), and a liquid crystal onsilicon (LCOS) chip.

Optionally, the beam steering optical element includes a 2-dimensionalarray of micro-mirrors to steer, pattern, and/or pixelate the multipleoutput light beams with varying color points by reflecting fromcorresponding pixels at a predetermined angle to turn each pixel on oroff.

Optionally, the 2-dimensional array of micro-mirrors are configured tobe activated by some of the one or more control signals received by thebeam steering driver from the microcontroller based on the inputinformation to manipulate the multiple output light beams withrespective color points being dynamically adjusted to provide a patternof color and brightness onto a surface of a target area or into adirection of a target space.

What is claimed is:
 1. A portable smart-lighting device configured forlight communication, the portable smart-lighting device comprising: anitrogen containing laser diode configured as a first pump-light devicewith an optical cavity comprising an optical waveguide region and one ormore facet regions and configured to output a first laser lightcharacterized by a first wavelength through at least one of the facetregions; a first wavelength converter optically coupled to a firstpathway to receive the first laser light from the first pump-lightdevice, wherein the first wavelength converter is configured to convertat least a fraction of the first laser light with the first wavelengthto at least a second wavelength that is longer than the first wavelengthand to generate a white-color emission comprising at least the secondwavelength; a package configured to support the nitrogen containinglaser diode and the first wavelength converter; a compact housingconfigured to have a surface member enclosing the package and an innerfixture, and have a front aperture; a controller including at least alaser driver module disposed at the inner fixture to drive and encodethe first laser light to carry a data stream; a portable power supplydisposed on the inner fixture to couple with the controller and one ormore input ports at the surface member; a beam shaper configured tocollimate the white-color emission with the front aperture; and a beamtransmitter combined with the front aperture to transmit a directionallight beam of the white-color emission carrying the data stream in alighting path.
 2. The portable smart-lighting device of claim 1 whereinthe nitrogen containing laser diode is a gallium and nitrogen containinglaser diode emitting a first peak wavelength in the violet wavelengthregion of 390 nm to 420 nm, the blue wavelength region of 420 nm to 480nm, or the green wavelength region of 480 nm to 540 nm.
 3. The portablesmart-lighting device of claim 1 wherein the first wavelength converteris comprised of a phosphor member including a ceramic yttrium aluminumgarnet (YAG) doped with Ce, or a single crystal YAG doped with Ce, or apowdered YAG comprising a binder material; and wherein the phosphormember has an optical conversion efficiency of at least 50 lumen peroptical watt.
 4. The portable smart-lighting device of claim 1 furthercomprising an infrared-emitting laser diode configured as a second laserdevice to output a second laser light characterized by a thirdwavelength in an infrared portion of the electromagnetic spectrum,wherein the second laser light is coupled to a second pathway toward thefirst wavelength converter to generate an infrared emission; wherein theinfrared-emitting laser diode is configured to lase the infraredelectromagnetic radiation characterized by a third wavelength in the 700nm to 1100 nm range, a wavelength in the 1100 to 2500 nm range, or awavelength in the 2500 nm to 15000 nm range.
 5. The portablesmart-lighting device of claim 4 wherein the infrared-emitting laserdiode comprises a semiconductor material selected from one or more ofSi, Ge, GaAs, InP, InGaAs, InAs, InAlAs, AlGaAs, AlInGaP, InGaAsP,InGaAsSb, GaSb, GaInSb, InSb, CdTe, [Hg_(x)Cd_(1−x)]Te; and wherein thesemiconductor material is comprised of a bulk material, doublehetereostructure, quantum well, quantum wire, or a quantum dotstructure.
 6. The portable smart-lighting device of claim 1 wherein thepackage configured to support the nitrogen containing laser diode andthe first wavelength converter is a surface mount device (SMD) packageand wherein a common support member configured to support the nitrogencontaining laser diode and the first wavelength converter is configuredfrom a base of the SMD package.
 7. The portable smart-lighting device ofclaim 1 further comprising a heatsink enclosed in the compact housingand attached with an inner structure to support the package of thenitrogen containing laser diode and the first wavelength converter. 8.The portable smart-lighting device of claim 1 wherein the laser drivermodule in the controller is configured to generate modulated lightsignal at a modulation frequency range of about 50 to 500 MHz, 500 MHzto 5 GHz, 5 GHz to 20 GHz, or greater than 20 GHz based on the datastream.
 9. The portable smart-lighting device of claim 1 wherein thecontroller is configured to receive the data stream via at least one ofthe one or more input ports through a wired or wireless communicationscheme.
 10. The portable smart-lighting device of claim 1 wherein thebeam shaper comprises one or a combination of more optical elementsselected a list of slow axis collimating lens, fast axis collimatinglens, aspheric lens, ball lens, total internal reflector (TIR) optics,parabolic lens optics, refractive optics, and micro-electromechanicalsystem (MEMS) mirrors configured to direct, collimate, focus thewhite-color emission and/or the infrared emission to at least modify anangular distribution thereof.
 11. The portable smart-lighting device ofclaim 1 wherein the portable power supply comprises a high-capacitybattery that is chargeable through a charging port disposed on thesurface member of the compact housing, wherein the high-capacity batteryincludes a circuitry with over-charge protection, over-dischargeprotection and short-circuit protection and includingnegative-temperature-coefficient protection.
 12. The portablesmart-lighting device of claim 1 is configured in a handheld flashlightdevice, security spot light device, bike-mounted light device,vehicle-mounted light device, drone-mounted light device for use inportable field applications including spotlighting, IR imaging,projection display, spatially dynamic lighting, WiFi LiFi, visible/IRlight communication, internet connection, general lighting, commerciallighting and display, defense and security, search and rescue,industrial processing, internet communications, or agriculture orhorticulture.
 13. The portable smart-lighting device of claim 4 whereinthe controller further comprises a pulse generator configured tomodulate the first laser light or the second laser light to generatepulsed signals for either visible-light depth sensing detection or IRlight depth-sensing detection or for dual detection with both visiblelight signal and IR light signal carrying the pulsed signals, whereinthe beam transmitter is configured to project either the white-coloremission or the infrared emission or both to a target of interest. 14.The portable smart-lighting device of claim 13 further comprises adetector disposed near the front aperture of the compact housing toreceive pulsed signals reflected from the target of interest to obtaindepth sensing information.
 15. The portable smart-lighting device ofclaim 1 further comprises a receiver disposed near the front aperture ofthe compact housing, the receiver is configured to detect a directionallight beam of a white-color emission or an infrared emission carryingthe data stream in a lighting path transmitted from a replicate portablesmart-lighting device.